Multicolor printing system for the silk-screen printing of compact discs

ABSTRACT

Apparatus is provided for the silk-screen printing of the top surface of a compact disc. Each compact disc is registered in a precise location prior to being printed. A compact disc is registered by an elongated registration pin which is raised vertically upwardly so as to intrude into the center hole of the compact disc from the bottom surface of the disc.

This application is a continuation of application Ser. No. 07/977,123,filed Nov. 16, 1992, now U.S. Pat. No. 5,313,882, which is acontinuation of application Ser. No. 07/665,242, filed Mar. 6, 1991, nowU.S. Pat. No. 5,165,340.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates, in general, to a system useful in thesilk-screen printing of relatively small, flat objects such as compactdiscs and floppy disks for computers. More particularly, it relates to asilk-screen printing system comprising in combination apparatus meansfor the automatic transport of compact discs in stepwise fashion,one-at-a-time, in a horizontally disposed circular-defined path, and thesilk-screen printing of such compact discs, means for automatic loadingof compact discs onto the transport apparatus one-at-a-time from avertically disposed stack of a plurality of such discs superposed oneabove the other in horizontal fashion and for off-loading printed discsfrom the transport apparatus one disc at-a-time, and providing them in avertically disposed stack of a plurality of horizontally disposedprinted discs superposed one above the other, and apparatus means forsupplying and receiving such compact discs in a plurality of verticallydisposed stacks. Even more particularly, the invention relates to thespecific transport means, load/off-loading means and supplying/receivingmeans used in the system combination.

2. Description of the Prior Art

Heretofore, others have invented apparatus for the silk-screen printingof compact discs with three colors. One such apparatus of whichapplicants are aware, and which has been used now for sometime,comprises, in general, a horizontally disposed, annular-shaped,rotatable member onto which compact discs are loaded one-at-a-time in acertain predetermined timed sequence and transported from a loading toan unloading station through the various work stations. As the transportmember rotates, the discs are transported from the loading station tothe various printing stations, at which stations the top planar surfacesof the horizontally disposed compact discs are each printedone-at-a-time with the color of the desired information. Followingprinting, the rotatable member transports the printed discs to a curingstation whereat the printing ink is cured in conventional fashion by,e.g., an ultraviolet (UV) curing means. Subsequently, the discs areunloaded from the rotatable member for further handling, as desired.

Although this known compact disc printing system does the job for whichit is intended, i.e., prints compact discs with 3-colors each having thedesired information, its use is accompanied, nevertheless, with certainproblems or disadvantages. Of critical concern is the location of thesilk-screen printing apparatus relative to the annular-shaped rotatabletransport member.

The silk-screen printing apparatus in this known device is supported onsupport means located outside the outer perimeter of the annular-shaped,rotable transport member. During printing of each of the compact discs,the silk-screen squeegee and flood bar moves radially inwardly acrossthe disc and rotatable transport member and then radially outwardly,retracting to its initial rest position outside the outer perimeter. Thetransport member, in this known apparatus, is fixedly secured at itsinner periphery, to a circular-shaped support member. Thus, as thesupport member is rotated, the transport member rotates. In essence, theannular-shaped transport member and circular-shaped support memberconstitute one rather large diameter rotatable member having only arelatively small diameter center opening. As a result, the spaceoccupied by the circular-shaped support member is not onlyunderutilized, but wasted as well. Moreover, as the silk-screen printingapparatus in this known device is located outside the perimeter of therotatable compact disc transport member, the printing system occupiesand takes up considerable floor space that may not be readily availablefor such an installation or is otherwise needed. Perhaps, moreimportantly, however, the location of the printing apparatus in thesystem now being used presents considerable difficulty to the operatorin set-up and change-over of the printing apparatus for the printing ofvarious different compact discs. This is due to the fact that thesilk-screen printing apparatus is so located relative to theannular-shaped transport member that it faces inwardly toward the centerof the apparatus. Thus, the operator, necessarily must bend over therotatable transport member in a somewhat contorted manner to accomplishchange over or other tasks associated with the printing apparatus.

Furthermore, in this known compact disc printing system, the compactdiscs, in general, are loaded and off-loaded onto and from the transportmember by means that are relatively complex involving numerousinterworking components in combination. This apparatus, like thetransport means, occupies considerable floor area that needs to bebetter utilized.

Subsequent to loading, the compact discs are each more preciselyregistered on the transport member prior to being transported to thefirst of the three printing stations. This is accomplished, in general,by a centering pin apparatus located vertically above the transportmember. Thus, in general, the centering pin is caused to intrude intothe center opening of the compact disc from the top surface thereofcausing the compact disc to move somewhat, even though a relativelysmall distance, across and in contact with the surface of the discfixture located on the transport member. This is highly undesirable,however, as the surface in contact with the fixture is the bottomsurface of the disc on which the recording is provided. This results inoccasional marring of the disc recording surface, leading to a disc thatmay be entirely unsuitable for sale.

Thus, there is need for a printing system for compact discs that notonly automates the entire process, but, also, takes up less floor space.Further, there is need for such a printing system wherein the relativelocations of the disc transport apparatus and printing apparatus aresuch as to also facilitate set up and change over or other tasks thatneed be accomplished on the silk-screen printing apparatus. And, thereis needed a means for centering of a compact disc on the transportmember prior to printing the disc that results in no, or at least less,marring or otherwise adversely affecting the disc.

SUMMARY OF THE INVENTION

The present invention has as one object the realization of a system forthe silk-screen printing of compact discs not attendant with thedisadvantages or problems now found in the use of such apparatus.

A further object of the invention is to provide a system for themulticolor printing of compact discs wherein the system, in general,comprises a horizontally disposed, rotatable, annular-shaped disctransport member in combination with silk-screen printing apparatussupported on an annular-shaped fixed support table located within theouter perimeter of such a member, and in overlapping relationship.

Another object of the invention is to provide such a printing systemhaving apparatus in combination with an annular-shaped transport memberfor the automatic loading of compact discs one-at-a-time onto thetransport member and for automatically off-loading of printed compactdiscs one-at-a-time from the transport member.

Still another object of the invention is to provide a system havingapparatus in combination with the loading/off-loading apparatus of theinvention for the automatic feeding and supply of compact discs to theloading mechanism of the loading/off-loading apparatus, the compactdiscs being provided in a plurality of vertically disposed uprightstacks each comprising a plurality of compact discs each horizontallydisposed and superposed one above the other.

A still further object of the invention is to provide a system havingapparatus in combination with the off-loading mechanism of theloading/off-loading apparatus for receiving printed compact discsone-at-a-time from the transport member and providing such in aplurality of vertically upright stacks, each comprising a plurality ofprinted compact discs superposed one above the other in horizontaldisposition.

A still further object of the invention is to provide apparatus for theregistration and centering of each compact disc on a disc fixture incombination with and located on the underside of the transport membercomprising a retractable centering pin which intrudes into the disccenter hole from the bottom surface of the compact disc, providingimproved load accuracy and elimination of marring caused by centeringthe disc after placed on disc fixture.

A key advantage of the printing system disclosed herein is that thesilk-screen printing apparatus is so oriented relative to theannular-shaped transport apparatus that the printing screen of thesilk-screen printing apparatus faces outwardly from the center of thetransport member, rather than inwardly toward the center. As a result,in general, the silk-screen squeegee strokes radially inwardly over thecompact disc and annular-shaped transport member and then retractsoutwardly to its rest position. Thus, the operator can more readily, andwith considerably more ease, set-up the silk-screen printing apparatusand change-over that apparatus for the printing of various differentcompact discs or other small flat objects, as needed.

A further advantage in the silk-screen printing apparatus being located,relative to the rotatable transport member, in the manner of theinvention disclosed herein, is that a safer environment is provided forthe operator.

Another advantage is that the printing system of this invention isrelatively compact in design compared to known multiprinting systems forcompact discs. Thus, quite advantageously, the transport apparatus andwork stations of the printing system of this invention not only take upand occupy a somewhat smaller amount of floor space than presently knownapparatus, a critical consideration in many installations, or potentialinstallations for such printing apparatus, but such apparatus makesbetter use of available floor space.

Another advantage of the printing system disclosed in this applicationis that compact discs can each be centered independently from oneanother and without marring of the recording surface.

Still another advantage of the invention is that the loading/off-loadingapparatus not only combines the loading and unloading mechanisms in oneunitary apparatus but such apparatus, most importantly, does not gateprinter speed, providing improved operating speed and efficiency. It,moreover, provides improved loading and off-loading accuracy.

Another important advantage of the printing system disclosed herein isthat such provides means for automatically feeding or providing a supplyof a plurality of compact discs to a loading apparatus one-at-a-time andfor automatically off-loading of printed compact discs from thetransport member and such compact discs are provided in a plurality ofvertically disposed stacks of a plurality of horizontally disposedcompact discs.

A further advantage is that vacuum supplied to a disc fixture can beclosed off in the event a compact disc is not loaded on the fixtureresulting in more efficient use of vacuum and providing a greater forceon compact discs that are located on the transport member.

A still further advantage of the invention is that a silk-screenprinting system is provided comprising, in combination, apparatus thatis of relatively simple construction and operation, compared to suchsystems now known.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, reference should behad to the following detailed description of the preferred embodimentsof the invention which is to be read in conjunction with theaccompanying drawings, in which:

FIG. 1 is a top plan schematic view of a system for the silk-screenprinting of compact discs according to the general aspects of theinvention showing in operative combination the automatic annular-shapedrotatable transport apparatus whereby compact discs are transportedthereon in predetermined spaced-apart locations to and through variouswork stations in a circular-defined path, the automaticloading/unloading apparatus, and the automatic disc supply/receiverapparatus;

FIG. 2 is a view in cross-section on a diameter of the annular-shapedtransport apparatus showing the mounting of a silk-screen printer in amanner according to one aspect of the invention relative to theannular-shaped transport member for the compact discs, theannular-shaped transport member, the means for indexing the transportmember, a compact disc fixture, the means for supplying vacuum to eachof the compact disc fixtures located on the top surface of the transportmember, the centering means for a compact disc, and the linkageconnecting the indexing means for the transport apparatus to the maindrive motor;

FIG. 3 is a diagrammatic view showing the linkage between the transportmember indexing means and the loading/off-loading apparatus of theinvention;

FIG. 4 is a top plan view of one of the compact disc fixtures providedon the top planar surface of the transport member without a compact discbeing located therein;

FIG. 5 is an exploded cross-sectional view of the fixture shown in FIG.4 taken at secant lines 5--5 and showing a compact disc located in thefixture;

FIG. 6 is a side view in elevation showing in part theloading/off-loading apparatus according to another aspect of theinvention, and its mounting on a support platform connected to the framefor the transport apparatus showing the loading mechanism of theloading/off-loading apparatus partially in section and the operatinglinkage connected to the index means for indexing the sucker armsprovided on the loading apparatus;

FIG. 7 is a view looking down onto the top surface of the horizontallydisposed arms of the loading/off-loading apparatus according to theinvention showing the linking mechanism with the drive shaft thereforfor operation of the load and off-load mechanisms and the operation ofthe pick and carry units associated therewith and the top view of thereceiver apparatus in operative combination with the off-loadingmechanism for receiving printed compact discs from the transport memberand providing such in a plurality of vertically disposed stacks each ofa plurality of compact discs superposed one above the other on aspindle;

FIG. 8 is a front view in elevation showing apparatus according toanother aspect of the invention for automatically feeding a supply of aplurality of compact discs in a plurality of vertically upright stacksto the loading mechanism of the loading/off-loading apparatus, eachstack comprising a plurality of horizontally disposed compact discs on astacking means supported on a spacer located on the indexing table;

FIG. 9 is a top plan view of the feed apparatus shown in FIG. 8 showingthe plurality of stacks of compact discs in spaced-apart manner andtheir circular-defined arrangement along with centrally locatedvertically upright elevator mechanism for raising of a stack of compactdiscs located at the load position to a predetermined vertical heightfor operative association with the loading mechanism of theloading/off-loading apparatus, the elevator mechanism being shown incross-section and showing the horizontally disposed fork means at thebottom thereof in operative combination with the bobbin of the stackingmeans on the top surface of which a stack of compact discs is providedfor lifting such vertically upwardly;

FIG. 10 is a partial longitudinal sectional view of the elevatormechanism showing the top portion of the screw and the carriage assemblyfor the fork member for raising a stack of compact discs to thepredetermined height;

FIG. 11 is a partial front elevation view showing the top portion of thescrew and the carriage assembly for the fork member along with therollers for guiding the vertical up and down travel of the carriageassembly;

FIG. 12 is an elevation view taken from the back of the elevatormechanism and showing the brake pads associated with the carriageassembly in operative association with the vertically disposed clamp barfor providing sufficient drag on the clamp bar to pivot the clampingmember at the base thereof so that such member provides a downward forceto keep the spindle base plate member in position;

FIG. 13 is a schematic view partially in cross-section showing theconnection of the base of the screw to a reversible drive motor for thedriving thereof in rotary manner and the linkage of the indexer to theindex table;

FIG. 14 is a top plan view of the compact disc supply apparatus likethat shown in FIG. 9 but showing the fork member in its retractedposition so that a new stack of compact discs can be indexed into placefrom the pre-load location to the load location for operativeassociation with the loading/off-loading apparatus; and

FIG. 15 is a partial view of the pick and carry unit of the loadingmechanism showing means associated therewith for closing off vacuum tothe sucker arm located at the load station on the rotatable disctransport member.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENTSTHEREOF

While the present invention will be described hereinafter withparticular reference to the accompanying drawings, it is to beunderstood at the outset that it is contemplated that the presentinvention may be varied in specific detail from that illustrated anddescribed herein while still achieving the desirable characteristics andfeatures of the present invention. Accordingly, the description whichfollows is intended to be understood as a broad enabling disclosuredirected to persons skilled in the applicable arts, and is not to beunderstood as being restrictive.

Referring now to FIG. 1 of the drawing, there is shown therein a system10 according to the invention for the 3-color silk-screen printing offlat objects such as compact discs 12 comprising in combination, ahorizontally disposed annular-shaped, rotable transport member (or dial)14, loading/off-loading apparatus generally referred to by referencenumeral 16, and compact disc sending (or feeding) and receivingapparatus 18, 20.

As best shown in FIG. 2, the annular-shaped transport member or dial 14is defined by inner and outer, vertically disposed, parallel, peripheraledges 22, 24 defined by predetermined inner and outer diameters, and topand bottom, parallel, planar, horizontally disposed surfaces 26, 28. Thedial 14 is fixedly connected in conventional manner to the rotary head30 of indexer 32 adjacent its inner peripheral edge 22 by means of boltsidentified generally by reference numeral 34. The indexer 32 is definedby a bottom, horizontally disposed planar surface 36 which rests uponand is fixedly connected to and supported by the horizontally disposedplatform 38 of frame 40. This is accomplished by usual techniques, e.g.by means of bolts 42 which extend through flanges identified byreference numeral 44 into threaded dead bores 45 provided in platform38. The frame 40 is supported by the concrete floor 46. If desired, itcan be fixedly connected in usual fashion to the floor.

The indexer 32 can be any commercially available indexer provided suchis capable of rotating the dial 14 and indexing it at every thirdlocation in the circular-defined path as hereinafter more fullydescribed. A standard index drive such as the "Model ED 810" availablecommercially from Ferguson Machine Co., St. Louis, Mo. will be foundsuitable in the practice of the invention disclosed herein. Suchindexing apparatus, in general, comprises a globoidal cam wherebyperpendicular input and output shafts can be driven in synchronousmanner, as desired. This indexing apparatus is provided in combinationwith an appropriate reducer for providing the desired torque on themotor driven input shaft 48.

Still referring to FIG. 2, it will be seen that, in this configurationof the invention, the input shaft 48 extends outwardly from the indexer32 adjacent the bottom thereof. On this horizontally disposed shaftthere is provided a pulley 50 in operative association with drive belt52. This drive belt rides around pulley 54 provided on drive shaft 56 inusual fashion. The drive shaft 56 is powered by a conventional electricmotor 58 fixedly connected according to usual technique to the frame 40.The drive shafts 48 and 56, as shown in FIG. 2, are horizontallydisposed and parallel to one another. Various motors can be used in thepractice of the invention provided such are capable of driving theindexer 32 and dial 14 at the desired production rates. Such will dependto some extent upon, among other considerations, the diameter of theannular-shaped transport member, the torque requirements, operativelyassociated apparatus, etc. A suitable motor can readily be selected bythose skilled in the art. One form of motor which has providedsatisfactory results in the practice of the invention is available fromLeeson. Such motor is characterized as a permanent magnet D.C., 2 hp.motor, capable of 2500 rpm top speed.

The transport member or dial 14 can be any size desired. Nevertheless,the larger the diameter, the greater will be the space in the workingarea taken up. A 60" diameter dial has proven quite satisfactory in thepractice of the invention and results in a compact printing systemtaking up a relatively small area of floor space. In general, theindexer 32 should be capable of operating at a nominal speed of about7.8 rpm. At such an operating rate, the printing system 10, hereinaftermore fully disclosed, will be capable of producing about 60 printedcompact discs 12 per minute. The indexer used is characterized by atorque capability of 20,000 inch-lbs, a dwell index ratio of 180degrees, and an accuracy of plus or minus 1.5 mils.

The transport member 14 is located in a horizontal plane just below thatdefined by a stationary, horizontally disposed, annular-shaped table orsupport member 60 on the top surface 62 of which is located silk-screenprinting apparatus identified generally by reference numerals 64, 66,and 68. The printing apparatuses are provided in predetermined,spaced-apart locations as hereinafter made more clear. Downstream fromthe printing apparatus, as shown in FIG. 1, there are provided curingstations, at which locations there are located conventional UV curingapparatus 70, 72. Various such apparatus are available and can readilybe selected by one skilled in the art, knowing the curingcharacteristics of the particular printing inks to be used. Curingapparatus 72 is optional and may not always be used. Such apparatusserves as a back-up curing means where longer curing times may benecessary for the curing of a particular ink. Upstream from printingapparatus 64 there is located a conventional cleaning station 74, thepurpose for which is to make certain the disc surface to be printed isfree of dust, etc. prior to application of the printing ink. Thus, thetop surface of each disc can be subjected to a blast of ionized air todissipate any charged on the dust particles and afterwards vacuumed topick-up and, remove any dust particles, etc. on the compact disc surfaceto be printed.

The fixed support table 60 is fixedly connected to, and maintained inhorizontal disposition above and parallel to the dial 14 by theannular-shaped, centrally disposed fixed body member 76. This can beaccomplished according to usual techniques by means of bolts referred togenerally by reference numeral 78, which pass through openings providedin the two members. The body member 76 is defined by top and bottom,planar, parallel, horizontally disposed surfaces 80, 82 and by inner andouter vertically upright peripheral surfaces or edges 84, 86 parallel,respectively, to peripheral edges 22, 24. The top surfaces 26, 62, and80 of the dial and fixed members are in planes parallel to one another.

The fixed body member 76, as will be readily seen in FIG. 2, is definedby two overhangs extending inwardly from the outer peripheral edge 86.The first, or upper overhang is defined by horizontally disposed planarbottom surface 88 and vertically upright circular-shaped edge 90. Thus,this overhang overlays the inner peripheral edge 92 of the fixed supporttable 60, allowing for fixedly connecting the two members together bybolts 78, earlier-mentioned. The second, or lower, overhang is definedby the annular-shaped horizontally disposed surface 94 and verticallydisposed surface, or peripheral edge 96, the latter surface beingparallel to peripheral edges 84, 86, and 92. The purpose for thislast-mentioned overhang will soon be made more clear.

The annular-shaped body member 76 is fixedly connected to the fixedportion 98 of the indexer 32 by conventional means (not shown). Providedin the fixed body portion 98 is a centrally located vertically disposedcylindrical-shaped opening 100 in which is located (FIG. 1) a verticallydisposed tubular-shaped member 102 at the top end of which is rotatablyconnected a horizontally disposed tubular-shaped arm 104. Thus, there isprovided means for enclosing all electrical wiring connected betweenvarious operating mechanisms and control station 106. The controlstation 106 can be rotated by the operator, as will be appreciated, toany work station or the like within the 270 degree arc, as shown by thearrows in FIG. 1 between the loading station and the stations just priorto the curing means 70. This enables the operator to control theoperation of the system at any point desired in this arc by merelyrotating the control arm 104 to the desired location around thetransport member 14. The control system and station 106 can becustomized with any control buttons or the like desired not only tostart/stop the printing system but to index the transport member,provide the loading mechanism on/off, etc. as desired. The providing ofany and all functional controls needed, or desired, in the practice ofthe invention, is all within the skill of the art.

It will be appreciated by those skilled in the art that fixed bodymember 76 can be machined out of a suitable piece of metal.Nevertheless, this body member can comprise, if desired, threeannular-shaped planar members of predetermined diameters fixedlyconnected together in horizontal disposition so as to provide the twooverhangs earlier described. Also, if desired, the support table 60 andfixed body member 76 need not be two separate members. The two memberscan be provided as one member, if desired, allowing the support table 60and fixed body member 76 to be in the same horizontal plane. In such acase, however, the lower overhang defined by surfaces 94, 96 will stillbe necessary, as later more fully appreciated. The importantconsideration is that a fixed support be provided for the silk-screenprinting apparatus whereby such apparatus can be located substantially,preferably completely, within the outer peripheral edge 24 of therotating dial 14, and facing outwardly toward that edge, as shown inFIG. 2, rather than toward the center of the dial. It will beappreciated also that the support platform 76 for the silk-screenprinters is not only superposed above the annular-shaped transportmember, but that such platform overlaps the inner portion of thetransport member to a large extent. Thus, there is provided, inaccordance with one aspect of the invention, a silk-screen printingsystem of relatively compact design and one offering more ready set upand easy change-over by the operator in the printing of differentcompact discs.

The circular-defined path traveled by the annular-shaped dial 14, asbest shown in FIG. 1, is divided, in the practice of the invention, into23 equally spaced-apart fixed locations or stations, indicated in thedrawing (FIG. 1) by reference numerals 1-23 appearing on the top surface26 of the rotatable member. It will be appreciated that such locationsare actually separate and distinct from, though defined by, therotatable member 14 and identify the precise locations for indexing ofthe rotatable member or dial 14 during the printing operation, as latermore fully described. A like number of locations are also provided onthe dial. These locations are each provided inwardly the same radialdistance from the outer peripheral edge defined by peripheral edge 24 ofthe dial and are located at points on an imaginary circle defined by theinwardly disposed locations. These locations are further defined byradii equally spaced about and intersecting with the imaginary circle.These intersections define, and this is a critical aspect of thisinvention, the precise location of the center point of thecircular-shaped well 124 provided in the compact disc fixtures 108provided at each location on the dial hereinafter more fully described.See FIGS. 2 and 4. As shown in FIG. 1, location No. 1 is the station atwhich compact discs 12 are loaded onto the transport member 14, as laterdescribed. And, station No. 21 is where the printed compact discs 12 areoff-loaded or unloaded from the transport member. These locationscoincide with the same numbered locations on the dial when the dial isat rest as shown in the drawing.

The compact disc fixtures 108 (FIGS. 4,5) are, as shown in the drawing,each defined by top and bottom planar, parallel horizontally disposedsurfaces 110, 112 and vertically upright inner and outer edges 114, 116and side edges 118, 120. These fixtures are each supported by andfixedly connected to the top planar surface 26 of the rotable transportmember 14, according to usual techniques, by means of threaded fastenersidentified generally by reference numerals 122. Each fixture 108 isfurther defined by a centrally located circular-shaped well 124 providedin the top planar surface 110 which is, in turn, defined by a bottomhorizontally disposed planar surface 126 parallel to top planar surface110, and a vertically upright peripheral edge or surface 128. In thebottom planar surface 112 of the fixture there is provided a well orplenum 130 concentric to well 124 defined by horizontally disposedplanar surface 132 parallel to surface 126 and the top surface 26 of thedial and vertically upright circular-shaped edge 134. The two wells arein communication with one another through the circular-shaped openingssuch as indicated by reference numerals 136, 138, (140, 142, not shown),provided in the bridge 144 defined by the planar bottom surfaces 126,132 of the wells 124, 130, the purpose for which will soon be disclosed.Although four such openings are provided, it will be appreciated that alarger number of or fewer openings can be provided, as desired, providedsuch function to accomplish the purposes hereinafter disclosed. In thewell 124, there is provided a circular-shaped disc support member 146upon which the compact disc 12 is supported for transport through thevarious work stations. This support member is provided withcircular-shaped openings 148, 150, 152, and 154 which extend through thesupport member from the top, horizontally disposed, planar surface 156to the bottom surface 158, parallel thereto. A like number of openingswill be provided in the disc support member 146 and bridge 144, theseopenings being concentric with one another whereby the openings in thedisc support member communicate with plenum 130.

Although not specifically shown in FIG. 5, an elongated tubular-shapedsleeve such as indicated by reference numeral 160 of conventionalmaterial is provided as commonly done for wear purposes, concentric withthe centers of well 124, 130 and in perpendicular disposition thereto.The bottom end of the sleeve, should terminate in the plane defined bythe bottom planar surface 112. Importantly, however, the top end ofsleeve 160 need terminate in the plane defined by the top surface 156 ofdisc 146, thus allowing the compact disc 12 to reside in the well 124and its top planar surface 162 to be in the same horizontal plane asthat defined by the top planar surface 110 of the disc fixture 108. Thisis of extreme importance so that during the silk-screen printing of acompact disc, hereinafter more fully described, the squeegee 67 willengage one continuous surface. The bottom of the silk-screen frame 65will be so located that it defines a plane parallel to the top surface110 of the fixture 108 and about 1/8 inch above the surface. Althoughnot shown in the drawings, the silk-screen frame can be supported inconventional manner.

At the location of each disc fixture 108, there is provided a verticallydisposed cylindrical-shaped opening in the dial 14 such as indicated byreference numeral 164. This opening provides communication between theplenum 130 and a conventional pneumatic operated two-way valve 166 (FIG.2) located underneath the dial 14 and fixedly secured thereto accordingto usual techniques. Connected to the valve 166 is one end of a tubularconduit 168, the other end being connected to the annular-shaped vacuummanifold 170 at its vertically disposed peripheral outer edge 172 and incommunication with the annular-shaped groove 174 provided in thehorizontally disposed annular-shaped top planar surface 176 thereof. Thevacuum manifold 170 is further defined by an annular-shaped bottomsurface 178 parallel to the top surface 176 and a vertically disposedplanar circular-shaped inner edge 180 parallel to the outer edge 172.Operatively associated with the manifold 170 at its bottom surface 178and located in predetermined spaced-apart locations in the bottomannular-shaped surface of the manifold are a plurality of elongated coilsprings 182, the purpose for which will soon be disclosed. The top endof each of the springs is located in a vertically upright dead bore 184provided inwardly in the bottom surface of the vacuum manifold, thebottom end being located in a dead bore 186 provided in andperpendicular to the top surface 26 of dial 14 and in direct oppositionto bore 184. As will be seen from FIG. 2 the top surface 176 of themanifold and the top surface 94 of the lower overhang are in contactwith one another, as are the vertically upright edges 96 and 180.Communicating with the annular-shaped groove 174 is a vertically uprightcylindrical-shaped opening 188 provided in the fixed body member 76.Although not shown in the drawings, this opening communicates with thesource of vacuum, as indicated by the arrow, a conventional vacuum pump.Thus, vacuum, as hereinafter further disclosed can be providedindependently to each of the compact disc fixtures 108 for holding acompact disc 12 securely against the disc support member 146 afterregistration and while being transported through the various workstations.

As the dial 14 rotates, it will be appreciated that the top surface 176and inner edge 180 of the vacuum manifold 170 are in sliding contactwith the opposed surfaces of the fixed body member 76. A tight sealbetween the top surface 176 of the manifold and the bottom surface 94 ofthe fixed body member is provided by the force of the vacuum exerted onthe manifold 170. Nevertheless, the compressed coil springs 182 willbetter ensure manifold 170 is in sealing engagement with bottom surface94. It will be appreciated that the manifold 170 should, most desirably,be of a material having low friction characteristics such as DELRINpolyacetal resin providing ease in sliding of the manifold surfacesagainst the fixed member surfaces as the dial 14 rotates. Although notshown in the drawing for sake of clarity, the manifold bottom surfacecan be operatively connected to the top surface of the dial by pins orthe like ensuring the rotation of the manifold. Somewhat less desirable,the vacuum manifold can, in some cases at least, be fixedly secured inconventional manner to the transport member 14.

Operatively associated with the valve 166, as shown in FIG. 2, is aconventional rotary actuator mechanism 190 (fixedly secured to the frame40-not shown) for automatically opening of the valve at that particularlocation on the dial when the transport member is indexed to the loadingstation (location #1) whereby vacuum is applied to the compact disc 12as loaded. A like actuator is located at the unloading station so thatthis particular valve can be automatically closed and the printedcompact disc 12' indexed to that station can be readily off-loaded fromthe transport member 14. Those skilled in the art will readilyappreciate that various conventional two-way valves and actuating meanstherefor can be used in the practice of the invention, provided theyaccomplish the functions described herein. The valve 166 used in thepractice of the invention is available commercially from ClippardInstrument Laboratories of Cincinnati, Ohio. The valve used is aconventional 4-way, double acting, stem operated detent valve. The valvecomprises, in general, an elongated horizontally disposed body member167 having an internal piston (not shown) capable of opening and closingoff the opening 169 in the valve connected to the vacuum conduit 168.The internally located piston is caused to operate, in general, byelongated horizontally disposed opposed members capable of reciprocalin/out operation, the upstream member being identified generally byreference number 171 provided in the valve body 167 on opposite sides ofthe piston. The actuator means 190 used in the practice of the inventioncomprises, in general, a lever 191 capable of rotary movement in aclockwise direction, at the loading station, and counterclockwise at theoff-loading station. When activated, the lever 191 pushes in the valvemember 171 at the loading station causing the valve 166 to be opened tothe vacuum source. At the off-loading station, the rotating lever 191operates to push in the opposing valve member 173 (not shown) to closeoff the valve. One form of actuator means which has been foundsatisfactory is a conventional pneumatic rotary actuator commerciallyavailable from SMC Pneumatic Inc. of Indianapolis, Ind.

As will be seen by reference to FIG. 2, a plurality of registering means192 is provided on the underneath side of the transport member 14 andfixedly connected thereto in conventional manner, in opposition to eachdisc fixture 108. The registering means 192 comprises, in general, anelongated, tubular-shaped housing 194 extending perpendicularlydownwardly from the bottom surface 28 of the transport member 14 incommunication with and concentric to the tubular sleeve 160. Locatedwithin the housing 194 is an elongated vertically uprightcircular-shaped registering pin 196 having an exposed rounded end 198,the purpose for which is to register the compact disc 12 as it is beingloaded onto the disc fixture 108 and to provide it in the preciselocation desired for printing just prior to application of vacuum to thefixture. The registering pin 196 is supported at its bottom end on acircular-shaped horizontally disposed annular-shaped base member 200surrounding the housing 194, having a planar top surface 202 parallel tobottom surface 28 of the dial. The registering pin is maintained in itsinoperative or retracted position by elongated spring member 204 whichsurrounds the tubular-shaped housing 194 the bottom end of which issupported on planar top surface 202 of the annular-shaped base member200. Operatively associated with the pin registering means at its bottomend 206 is a conventional means 208 (fixedly connected to frame 40) foractuating the operation of the registering means. This actuating meanscomprises, in general, a conventional two way piston having a verticallyupright rod 210 connected thereto and in operative association with basemember 200. Thus, as the piston is actuated, on the loading of a compactdisc onto the transport member 14, the piston rod 210 rises verticallyupwardly causing the base member 200 and the registering pin 196 to beraised vertically upwardly engaging the centerhole 212 of the compactdisc as it is being loaded onto the disc fixture and causing such to beprecisely centered on the disc support member or pad 146 just prior toapplication of vacuum. The compact disc is importantly centered prior tobeing deposited on the disc support member. On the application of thevacuum to the disc fixture, the registering pin 196 is automaticallycaused to retract by downward expansion of the compressed spring 204.Importantly, however, the pin does not retract until the vacuum isapplied to the disc. The pin is retracted so that the rounded end of thepin is below the plane of the fixture's top surface 110 and below thebottom surface of the compact disc. Quite advantageously, a registeringmeans is provided in association with each disc fixture allowing eachcompact disc to be precisely registered prior to being printed. Theregistering pin used is of stainless steel and is located within abronze bushing providing good bearing characteristics, according toconventional technique, such as to provide high tolerance, e.g.approximately 2-3 mils smaller diameter, relative to the center hole ofthe compact disc.

As earlier disclosed, the number of fixed, spaced-apart locations orstations defined by the circular-defined path of travel of the rotatabledial is 23. This need not necessarily, however, always be the case. Thenumber of fixed stations, hence the number of disc fixtures 108 thatneed be provided with any particular dial or printing operation, willdepend upon a number of factors, as appreciated by those skilled in theart, e.g., the number of colors to be applied to the compact disc, thediameter of the dial, the width of the printer screen, and the widthdimensions of apparatus at other work stations such as the UV curingapparatus. As is well known by those skilled in the silk-screen printingart, the width of the printer screen will depend primarily upon thewidth of the image to be printed. In the practice of this invention,three colors are applied to each compact disc, each color necessitatingcuring before application of the next color. Thus, in order to providethe most compact printing system, determined largely by the outsidediameter of the annular-shaped dial 14, the three different colors to beapplied in this embodiment of the invention necessitates that threecomplete rotations of the dial be made for each compact disc to beprinted, one color being applied each rotation, as later more fullydisclosed. Each of the first two colors applied need be at leastpartially cured prior to application of the next color, as those skilledin the silk-screen printing art readily appreciate that wet ink cannotbe applied on wet ink. That being the case, an indexer capable ofindexing each third location defined by the circular path of travel isnecessary. Then, one must, in general, taking into consideration thenumber of work stations to be provided and their respective widthdimensions, determine the number of locations to be provided and thedistance between each location. In general, where three colors are to beprinted on a compact disc, each in a separate revolution of thetransport member, any number of odd numbered stations can be provided aslong as such is not divisible by three. As an example, in three colorprinting as herein disclosed, the minimum number of stations will bedetermined largely by the number of work stations involved, their widthdimensions and the required spacing between each work station. Themaximum number of stations for indexing will be largely determined bythe desired minimum outer diameter of the dial. The optimum dialdiameter, number of fixed stations, etc. can readily be determined bythose skilled in the art. It will be appreciated also that in thebroader concepts of this invention, such is not limited to three-colorprinting.

The structure of the rotatable transport member, quite advantageously,allows the silk-screen printing apparatus 64, 66, 68 to each beinstalled relative thereto so as to provide ready change-over by theoperator to other printing operations. Thus, as will be readilyappreciated by reference to FIG. 2, the silk-screen frame of eachprinting apparatus, as indicated generally by reference numeral 65,extends radially outwardly from the center of the rotatable transportmember 14 and the fixed support member 60 on which the silk-screenprinting apparatus is fixedly mounted. Although not shown in FIG. 2 forsake of clarity, the silk-screen frame is mounted in conventionalfashion to the printer apparatus. The silk-screen printer 64, as shownby the drawing, is mounted so that the outer extent of the silk-screenframe 65 lies largely within the outer perimeter of the rotatabletransport member. Although not shown in the drawings for such does notaffect the basic concepts of this invention, other than as disclosedherein, the frame 65 need be supported at its outer edge. This canreadily be accomplished by those in the art. The squeegee 67 as shown bythe arrows in the drawing (FIG. 2) moves radially inwardly in ahorizontally disposed plane across the compact disc 12 during theprinting cycle. As will be readily appreciated this orientation of thesilk-screen printer provides not only for easier changeover to otherprinting operations but also allows for easier set up and otheroperations by the operator, as well as a safer working environment. Thesqueegee, moreover, is mounted so that it can be raised verticallyupwardly in a clockwise pivoting manner, as desired.

The loading/unloading apparatus 16, as best seen in FIG. 6, is fixedlysupported on a horizontally disposed platform 214 fixedly connected tothe frame 40 in a conventional manner (not shown). The platform 214defines a horizontally disposed planar surface 216, parallel to theplane defined by the top surface 26 of the rotatable transport member,for supporting the vertically disposed load/unloading apparatus 16. Thisapparatus, as may be better appreciated by reference to FIG. 7,comprises a somewhat T-shaped frame 218 comprising a horizontallydisposed top member comprising arms 220, 222, of equal length anddimensions and a circular-shaped upright member 224 perpendicular to thecross-bar formed by the arms 220, 222 and depending verticallydownwardly therefrom. The upright member 224 intersects the arms of theT at their inner ends and is located equidistantly inwardly from each ofthe ends, as best seen in FIG. 7. The horizontally disposed arms 220,222 are defined by upper and lower spaced-apart, parallel planarsurfaces 226, 228 and 230, 232, (not shown) respectively, the topsurfaces lying in the same horizontal plane, as do the bottom planarsurfaces. The arms 220, 222 are further defined by vertically uprightinner and outer edges 234, 236, 238, 240, respectively, connecting thetop and bottom surfaces of each. The outer edges 236, 240 of the armstaper inwardly toward one another at predetermined equal angles and arejoined at their inner ends (FIG. 7) being tangent to and defining thearc of a circle having the radius of the circular-shaped upright member224. The inner edges 234, 238 of the arms are joined together at theirinner ends defining an obtuse angle A bisected by a diameter of thecircle defined by the outer peripheral surface 242 of the upright member224. The arms 220, 222 terminate at their outer ends in verticallyupright rounded edges 244, 246 each of which provides a smooth curvedefined by a semicircle the ends of which join to the respective outerand inner edges of arms 220, 222. As seen in FIG. 7, the outer and inneredges of each of the arms taper inwardly toward one another from theirrespective inner ends being tangent to the circle defined by therespective rounded outer edges 244, 246. The angle "A" formed by theinner edges of the arms at their inner ends can vary somewhat, dependingat least in part on the diameter of the dial, the spacing between andlocation of the compact disc fixtures 108 provided on the dial 14, thenumber of locations to be indexed, the length of the arms 220, 222, aswill be appreciated. The optimum angle A and configuration of theloading/unloading apparatus, in any particular application, is wellwithin the skill of the art.

As shown in FIG. 6, the vertically upright cylindrical-shaped member 224terminates in a horizontally disposed base member 248 perpendicularthereto. This base member rests upon and is supported by thehorizontally disposed planar surfaced top member 250 of the housing 252for a conventional index drive located therein. The bottom member 254 ofthe housing is defined by a horizontally disposed planar bottom surface256, parallel to the upper surface of the top member 250 and to thehorizontal plane defined by the upper surfaces of the arms 220, 222. Thebottom member 254 is spaced vertically upwardly a predetermined distancefrom and is fixedly secured according to conventional manner to theplatform 214, the horizontally disposed planar surface 216 thereof beingparallel to the plane defined by the said upper surfaces of the arms,and to the upper planar surface 26 of the rotatable transport member.This spacing will depend, among other considerations, upon thehorizontal location of the platform 214 on the frame 40 to which it isfixedly secured, the distance that the planar top surface 26 of the dialis located above the floor, and the vertical length of the housingupright member 224.

Various indexers can be used for operation of the loading/unloadingapparatus, as hereinafter more fully described. The main requirements,in this particular embodiment of the invention, are that such have adwell index ratio of 180 degrees and that such be three-stop. One formof indexer that will meet the requirements of the invention and whichhas provided satisfactory results in the practice thereof is availablefrom Emerson Power Transmission Corp., Wheeling, Ill. under the tradedesignation Camco Custom Cams, RG40.

Turning now again to FIG. 7, it will be seen that the arms 220, 222 areeach provided with elongated rectangular-shaped openings 258, 260defined by vertically upright spaced-apart elongated edges 262, 264 and266, 268, and vertically upright spaced-apart inner and outer end edges270, 272 and 274, 276, respectively. Located within therectangular-shaped openings 258, 260 are elongated arms 278, 280pivotally mounted in the respective opening at their mid-points forvertical up and down motion, as later more fully described (See FIG. 6).Affixed to the top surface of the arms 220, 222, and located at theirrespective outer ends are circular-shaped vertically upright housings282, 284. These housings define, respectively, cylindrical-shapedupright interior cavities closed at the top end thereof and open at thebottom identified by reference numerals 286, 288. Projecting inwardlyand integral with the respective housings 282, 284 are mountingappendages 290, 292 defined by vertically upright planar inner surfaces294, 296. The appendages are provided with horizontally disposedcircular-shaped openings 298, 300 extending inwardly from the planarsurfaces 294, 296 and communicating, respectively, with the cavities286, 288. Located inwardly from the inner ends of the arms 220, 222 andfixedly connected to the top surfaces thereof are mounting members 302,304. These members are provided, respectively, with horizontallydisposed, circular-shaped, elongated openings 306, 308 of the samediameter as openings 298, 300. The openings 298, 306 and 300, 308 are indirect opposition to one another, respectively, and in the samehorizontal plane, defining imaginary centerlines connecting the centerof the circle defined by the outer surface 242 of the vertically uprightmember 224 and those circles defined by the respective circular shapedhousings 282, 284 and outer end edges 244, 246.

As shown in FIGS. 6, 7, horizontally disposed drive shafts 310, 312 areprovided in parallel association with the upper surfaces of therespective arms 220, 222. These drive shafts are located on theabove-mentioned imaginary centerlines and are mounted for rotation andsupported in conventional bearing members adjacent their ends in theelongated openings 298, 306 and 300, 308. At the ends of the driveshafts 310, 312, respectively, are provided conventional beveled gears314, 316 and 318, 320. The beveled gears 314, 318 provided at the innerends of the shafts 310, 312 mesh with a beveled gear 322 provided at thetop end of the elongated drive shaft 324. This drive shaft is rotatablymounted (not shown) according to conventional techniques within uprightmember 224 so as to be vertically upright. The lower end of this uprightdrive shaft 324 is operatively connected by conventional means to theupwardly defined output shaft 326 of index drive 252 (FIG. 3). The indexdrive is provided with horizontally disposed input shaft 328perpendicular to shaft 326, and a horizontally disposed drive shaft 330,in opposition to shaft 328, the purpose for which will later beexplained.

The beveled gears 316, 320 at the outer ends of the elongatedhorizontally disposed drive shafts 310, 312, respectively, mesh withbeveled gears such as identified by reference numeral 332 provided atthe top end of the vertically upright elongated drive shaft 334rotatably mounted in conventional manner in the loading mechanismidentified, in general, by reference numeral 336. See FIG. 6. Theoff-loading mechanism 384 is of identical construction and operation asthe loading mechanism; accordingly, only the loading mechanism will bemore particularly described hereinafter.

As shown in FIG. 6, the top end of drive shaft 334 is mounted in aconventional bearing member 338 located in the top end of the housing282 and centrally within the circular-shaped cavity 286. A bushing 340is provided in the lower end of housing 282 in usual manner throughwhich the drive shaft 334 passes and which provides rotatable supportfor maintaining the shaft 334 in the upright position. The bottom end ofdrive shaft 334 intrudes into the elongated vertically disposed cavity342 of a conventional, commercially available spline shaft 343 and isfixedly secured therein according to usual technique. The spline shaft343 is fixedly located in conventional manner in the top portion of theelongated vertically disposed centrally located cavity 345 provided inthe rotatable member 344. Thus, as the drive shaft 334 is rotated inhorizontal and clockwise manner the rotatable member 344 will be rotatedtherewith. The rotatable member 344 is mounted for rotation inconventional bearings 348, 350 located in a circular-shaped housing 352.The housing 352 is provided with horizontally disposed outwardlyprojecting guide means 354, 356 in each of which is provided avertically upright cylindrical-shaped opening (not shown) through whichpasses a vertically upright cylindrical-shaped rod or guide shaft 358.The top end of shaft 358 is fixedly located (not shown) in the bottom ofhousing 282. Thus, the guide shaft 358 insures the movement of theloading mechanism 336 in a vertical upright and downward motion on driveshaft 334, the reason for which will be disclosed hereinafter.

Connected to housing 352 in conventional fixed manner, e.g. by capscrews (not shown), is a connecting member 359, to which is pivotallyconnected the bottom end of vertically disposed link 360, the top end ofwhich is pivotally connected to the elongated arm 278 at its outer endwhich, as earlier disclosed, is mounted for pivotal up and down motionat pivot point 362. The opposite or inner end of the arm 278 ispivotally connected to the top end of the vertically upright connectingarm 364 the bottom end of this arm being pivotally connected to thefront end of the horizontally disposed elongated pivot arm 366. The backend of this pivot arm is pivotally connected to mounting fixture 368,this fixture being fixedly secured in conventional manner to thehorizontally disposed platform 214 which supports the load/unloadapparatus 16. The pivot arm 366 is pivotally connected at a pointbetween its back and front ends to the outer end of the cam follower370. The inner end of the cam follower is operatively associated with aconventional rise and fall cam 372 rotatably mounted on output driveshaft 330 of the indexer 252. The pivot arm 366, as best seen in FIG. 3,extends toward the dial 14 and is in perpendicular disposition to thecam follower 370 and drive shaft 330, these last-named members beingparallel to one another.

On input shaft 328, directly opposed to output shaft 330, there ismounted a cam 374, like cam 372. The cam 374 is operatively associatedwith one end of the horizontally disposed cam follower 376, the oppositeend thereof being pivotally connected to the elongated horizontallydisposed pivot arm 378. This arm is pivotally connected at its back endto mounting fixture 380 and at its front end to the bottom end ofvertically upright connecting arm 382. The top end of connecting arm 382is pivotally connected to the inner end of pivot arm 280. The connectingarms 364, 382 are located in vertically upright spaced-apart planesparallel to one another and in the same vertically upright planeperpendicular to the said upright parallel planes. The horizontallydisposed pivot arms 366, 378 are located in vertically disposed planesspaced-apart from one another and parallel to those spaced-apart planesin which the connecting arms 364, 382 (FIG. 3) are located. The pivotarms 366, 378 are located in the same horizontal plane parallel to theplanar surface 216 of the supporting platform 214. Thus, on rotation ofinput shaft 328, the output shaft 330 from the indexer 252 rotates inunison therewith, and the cams 372, 374 rotate in unison. Thus, thepivot arms 366, 378 cause the connecting arms 364, 382 to risevertically upwardly and downwardly in unison with one another, and inthe same timed sequence, i.e., when connecting rod 382 moves verticallyupwardly, connecting rod 364 moves in the same manner and to the sameextent.

As the top ends of the connecting arms 364, 382 are pivotally connected,respectively, to the horizontally disposed arms 278, 280, these armslikewise move in synchronization with one another and to the sameextent. Thus, when the connecting arms 364, 382 are caused to movevertically downwardly through the action of the respective cams 372,374, the arms 278, 280 are caused to move upwardly at their outer ends,at the same time, and to the same extent. This action causes therespective loading mechanism 336 and unloading mechanism designatedgenerally by reference numeral 384 (FIG. 7) to move vertically uprightin sequence and to the same predetermined extent, as hereinafter furtherdisclosed. And, when the connecting arms 364, 382 are caused to movevertically upwardly, the arms 278, 280 are caused to move downwardly attheir respective outer ends causing the respective loading, unloadingmechanism 336, 384 to move vertically downwardly in synchronization withone another. The extent of these vertical up and down movements of theloading and unloading mechanisms will depend primarily upon the extentof the vertical up and down movement desired for the loading andunloading mechanism, taking into consideration the overall operation ofthe system disclosed. Once this is determined, the location of theloading and unloading mechanisms on their respective drive shaftsrelative to the bottoms of the respective housings 282, 284 can bedetermined. Thus, referring to FIG. 6, the vertical up and down movementof loading mechanism 336 will be limited then, in general, by thevertical distance between the bottom of housing 282 and the top surface386 of the housing 352, and the location of the spline shaft on thedrive shaft 334. The downward movement is limited by the spline shaft,the upward movement being limited by the bottom of the housing. Thevertical up/down movement of the loading mechanism is insured by theguide shaft 358, a similar guide means being provided with the unloadingmechanism 384 but not specifically shown in the drawings.

On input shaft 328 there is provided a conventional pulley 388 (FIG. 3)around which passes one end of a drive belt 390 according to usualmanner, the other end of the belt being operatively engaged with thepulley 392 provided on the elongated rotatable shaft 394, this shaftbeing in parallel disposition to input shaft 328. The pulleys 388, 392are so located on their respective shafts as to provide belt 390 inperpendicular disposition to each according to usual technique. On theelongated shaft 394 there is provided a pulley 396 over which rides oneend of a drive belt 398, the other end being operatively associated withthe pulley 400 provided on the driven output shaft 402 of indexer 32.The shafts 394 and 402 are parallel to one another. Though notspecifically provided for in the drawings, a slip clutch can be providedin combination with pully 388 and/or elsewhere, to avoid damage in theevent of some malfunction, according to good engineering practice.

At the outer end of the drive shaft 394 there is provided a conventionalencoder 404 coupled to the shaft 394 in usual manner by means of a thinwall or spline coupling 406. An encoder found suitable for use in thepractice of the invention is an incremental optical encoder, availablefrom Idec Izumi Corp., Sunnyvale, Calif. The thin wall coupling used canbe obtained from Winfried M. Berg, Inc., East Rockaway, N.Y. Thefunction of the encoder 404, as will be appreciated, is to track therotation of the rotatable transport member so as to automaticallyprovide a particular predetermined compact disc fixture 108 at apredetermined location, identified by reference numerals 1-23, in thetransport member's circular-defined path of travel according to thepredetermined operation of the cam or indexer 32 in the system. Thus,the air valve actuator 208 will be fired at the precise time that acompact disc 12 is being loaded onto the disc fixture 108 then locatedat the loading station, i.e., station No. 1, whereby the centering pin196 will rise vertically upwardly, intruding into the center-hole 212 ofthe compact disc. Thus, the compact disc 12 is centered prior to itsactually contacting the disc support member 124 located in the disc well146. As a result there is no movement of the compact disc across thesurface of the support member that will result in damage to thedownwardly disposed recording surface of the disc. At the precise time,the centering pin 196 will be caused to retract by the ProgrammableLogic Control (not shown). Thus, the actuator 190 causes the two-wayvalve 166 to open, providing vacuum to the now centered disc. Thisvacuum is retained on that compact disc until the disc has been printedwith each of its 3 colors, the ink cured, and that particular discarrives at station No. 21 on its third time around the circular-definedpath of travel for off-loading from the transport member 14. The encoder404, once a disc has been loaded at station No. 1, tracks the indexingof that particular compact disc 12 through the various work stations,and finally to the station at which it, now printed as desired, isoff-loaded. At the off-loading station, the actuator 190 is caused tooperate at the precise time whereby the rotary lever 191 operates incounterclockwise fashion pushing in the two-way on/off valve means 171closing off the suction to that particular disc receptacle so that thecompact disc can be off-loaded. Although not specifically shown in thedrawings, it is preferred that means be provided in association with thetransport member for sensing the actual loading of a compact disc onto adisc fixture. Various sensing means can be provided to perform thisfunction, as later more fully disclosed. Such a sensing means will be solocated as to determine the presence of a compact disc, on the flyso-to-speak, as the arm on the pick-and-carry unit of the loadingmechanism holding such a compact disc rotates around to load the disconto the transport member, later more fully disclosed. On sensing thepresence of a compact disc, this will trigger operation of theregistering pin and providing of vacuum to that particular disc fixture.Importantly, however, if no compact disc is sensed, the actuator means190 will not be caused to function and the vacuum valve on the discfixture will remain closed. Thus, the efficiency of the vacuum system tothe disc fixtures will be better maintained, as a line is not open tothe atmosphere due to the absence of a compact disc in a particular discfixture. This being the case, the vacuum force provided initially willremain constant to all the disc fixtures and not be lessenedinadvertently from time-to-time.

Various other encoders are available commercially and may be foundsuitable in the practice of the invention. One such encoder is availablefrom Dynapar Corp. of Gurnee, Ill. Other couplings may also be foundsuitable for use in this invention. The main requirement is that suchdevices be rotationally stiff and flexible in the other five axis. Suchcouplings are also available from Dynapar Corp. under the tradedesignation Flex-E-Grip. In general, the encoder to be used should becapable of 60 counts/minute and be able to track the location of therotatable dial 14 and determine its location at any particular time inthe operation of the printing system disclosed herein. The ProgrammableLogic Control (PLC) (not shown) is available from OMRON Electronics Inc.of Schaumberg, Ill. under the trade designation Omron SYSMAC C200H.Other programmable control devices, however, as conventionally used maybe found satisfactory in the practice of the invention and the automaticoperation of the system and the synchronization of its variouscomponents as described in this application provided that such acontroller provides input/output characteristics compatible with theoperation of the various components and their operative combination inthe printing system disclosed herein, as later believed made somewhatmore clear. The programming of the PLC to provide automatic andcooperative operation of the various components of the system disclosedherein can be readily accomplished by a skilled programmer.

It will be appreciated by those skilled in the art that each of thecomponents of this printing system involves certain control circuits toprovide the automatic operation desired. And, that the system overallincorporates control circuits for the automatic and synchronousoperations involved. Nevertheless, it is believed well within the art toprovide the various, and most suitable, electronic components needed tocontrol and operate the various apparatus components making up thisprinting system and to attain any of the various functions andoperations as and when desired.

Referring again to FIG. 6, the elongated rotatable member 344 is fixedlyconnected at its bottom end, according to conventional techniques, to arotatable pick and carry unit identified generally by reference numeral408. The elongated cavity 345 is in communication with the inlet of eachof the cartridge valves provided at the base of the cavity such asindicated by reference numerals 410, 412, the reason for which will soonbe explained. Extending outwardly from the bottom of the pick and carryunit are three horizontally, disposed support arms 414, 416, 418 eachsupporting the top end of a vertically disposed elongated sucker arm420, 422, 424, respectively. The support arms 414, 416, 418 are of equallength, the rotation of which defines a circular-shaped path in ahorizontal plane parallel to that plane defined by the rotatabletransport member 14. As will be somewhat better appreciated by referenceto FIGS. 1, 7, it will be seen that the support arms are radiallydisposed and equally spaced-apart from one another, in this case 120degrees apart. This spacing is determined, as will be appreciated bythose skilled in the art, by the dimensions of the rotatable transportmember, and the spacing between the compact disc fixtures 108, amongother considerations.

To the bottom of the sucker arms are fixedly secured conventional rubbersuckers 426, 428, 430. As shown in FIG. 6 of the drawings, the suckersare mounted to the ends of the respective sucker arms so that the cupface of each is horizontally disposed, facing downwardly, and in thesame horizontally disposed plane, parallel to the support surface 216.The sucker 426 is provided with a centrally disposed opening (not shown)in its base which communicates with the bottom end of the verticallydisposed, elongated circular-shaped opening 432 provided in sucker arm420. The elongated opening 432 communicates at its top end with theouter end of the horizontally disposed elongated opening 434 provided inthe support arm 414. The inner end of the tubular-shaped opening 434communicates with the bottom end of the vertically disposed elongatedopening 436, the top end of which communicates with the outlet ofcartridge valve 410. Though the drawings show a single sucker cup, forsake of clarity, such a component having three cups has been used in thepractice of the invention. These units are available commercially fromVicas Manufacturing Co., Inc. and are more specifically identified as a" mini-bellows style coupling."

Protruding outwardly from the loading mechanism housing 352 is a conduitmeans 438 for connection as indicated by the arrow, to a suitable vacuumsource (not shown). The conduit 438 communicates with the internalcavity 440 provided in the housing 352 defined by its verticallydisposed inner, circular-shaped peripheral surface. Although the outervertically disposed peripheral surface 442 of the rotating member is inclose proximity to the inside wall surface of housing 352 definingcavity 440, these surfaces are shown some distance apart in the drawingsfor sake of clarity. The rotable member 344 is provided on its outsidesurface with a horizontally disposed annular-shaped groove 444 in directopposition to the inlet in the housing 252 for the vacuum conduit 438.The annular-shaped groove 444 is provided at its bottom with a pluralityof openings (not shown) which communicate with the elongated cavity 345.Thus, vacuum is continuously applied to each of the sucker arms 414,416, 418 and the associated suckers during operation of the printingsystem, except as hereinafter further disclosed. This results from thefact that the groove 444 functions as a manifold, such groove alwaysbeing directly opposite the inlet end of the vacuum conduit 438 as therotatable member 344 rotates. Although not shown in the drawing for sakeof clarity, it will be appreciated that a valve, like valves 410, 412 isprovided in association with the sucker arm 422. In another embodimentof the invention, rather than providing a vacuum manifold 442 such asshown in the drawings opposite the inlet for the vacuum connection 438,that portion of the rotable member 344 can be provided of somewhatlesser diameter, terminating in a horizontally disposed surface justshort of the top of the bearing 350. Thus, a U-shaped cavity facingoutwardly will be provided for housing the inner portion of the bearingand providing an annular-shaped horizontally disposed surface as a partof the rotating member. In this surface then can be provided verticallydisposed tubular-shaped elongated openings communicating at theirbottoms with the respective three valves, e.g. as identified byreference numerals 410, 412. The third valve is not shown in thedrawing. The top end of each such opening will communicate with thevacuum chamber provided and which communicates with the inlet 438 to thevacuum source.

The stems of the cartridge valves, as seen in FIG. 6, extend radiallyoutwardly in horizontal disposition and are each engaged by a springloaded member or actuator 446, in this case a spherical member such as aball bearing (3/8" dia), a portion of which extends outwardly through acircular-shaped opening 448 provided in the bottom portion of housing352 as shown in the drawing. The member 446 is spring loaded accordingto conventional techniques so that it is biased away from the valvestem. As will be appreciated, the suction cup on the vacuum to that armat the loading station will need be deactivated so that the compact discbeing carried by the pick and carry unit can be dropped off, onto thedisc fixture. And, with respect to the off-loading mechanism, the vacuumwill need be deactivated to the suction cup located on that arm, overthe receiving apparatus. To accomplish this, the portion of the springloaded member 446 protruding outwardly from the opening 448 isengageable by a vertically disposed planar-shaped ramp member 450, asshown in FIG. 15 of the drawing. This ramp member is defined by a backsurface 409 and a surface 411 which tapers inwardly toward the loading,or off-loading mechanism, as the case may be, from top to bottom. Thus,as the loading mechanism 336 moves vertically downwardly, at locationNo. 1, later more fully described, the valve stem (not shown) engaged bymember 446 is depressed sufficiently to allow vacuum to the suction cupat that location, which is always on to each of the sucker arms, to beinterrupted momentarily, allowing a compact disc 12 to be dropped off,e.g., onto the compact disc fixture 108, located at station No. 1. Whenthe spring loaded member is depressed, the conduit leading to the suckerarm of concern is blocked. Thus, atmospheric air back fills into thesucker arm via the sucker cup, resulting in no vacuum force on the discand such falls off the pick and carry unit. The same operation occurswith the off-loading mechanism with respect to the suction cup carryingthe compact disc to be dropped onto the receiving apparatus. Thus, thelocation of each such ramp 450 will need be such as to accomplish thesefunctions, taking into consideration the relative locations of theparticular valves involved relative to the respective verticallydisposed sucker arms. In general, the valves and spring loaded membersshould be so located as to be radially between two next adjacentelongated support arms, as this will allow mounting of each of the rampsso as not to interfere with the elongated arms or the vertical up anddown motion of either the loading or off-loading mechanisms. Althoughnot shown in the drawing, the particular location of the ramp and themanner of mounting the same can be readily determined by those in theart.

Various valves and actuating members to open and close the same, as andwhen desired, may be found suitable for use in the practice of theinvention. One such a valve is commercially available from ClippardInstrument Laboratories, earlier mentioned, under the trade designationMJVO-3C. This is a minimatic 3-way cartridge poppet valve which canexhaust around the stem, a requirement in this particular constructionof the loading and unloading mechanisms, whatever valve may be used. Thevalves are located each in horizontal disposition so that the inlets ofeach are in communication with the bore 345 and the outlet incommunication with a sucker arm.

The unloading mechanism 384 is of like construction and function as theloading mechanism 336. The two mechanisms operate in timed sequence withone another with the operation of the transport member 14, and thesending and receiving apparatus 18, 20, later more fully described. Theloading/unloading apparatus 16 communicates with the rotatable transportmember 14. This apparatus is, in turn, tracked by the encoder 404,according to usual technique, which determines if all the variouscomponents are located in the right position for operation. The encodercommunicates with the PLC in conventional manner so that the operationof the loading and unloading mechanisms is not only synchronized in thedesired manner with the operation of the transport member but so thatall desired operations of each is controlled automatically, the same asare those of the sending and receiving apparatus. Thus, when theprinting system is in operation, in general, a compact disc 12 will beloaded onto the transport member 14 at station No. 1 by one arm of thepick and carry unit, e.g., arm 414, and at the same time a compact disc12', which has been fully printed, as desired, will be off-loaded fromthe transport member 14 by one arm, e.g., arm 415 (FIG. 7) of theunloading mechanism 384 at station No. 21. More about the operation ofthe system and the loading/unloading apparatus later. At the same time,a compact disc 12, is being picked up by the next adjacent sucker armcounter-clockwise from the sender apparatus 18 and a printed disc isbeing deposited on the receiving apparatus 20 in a stack.

Turning now to FIG. 8 of the drawing, there is shown, in somewhatgreater detail, the apparatus means 18 for automatically sending, i.e.feeding or supplying, a plurality of compact discs 12 to the printingsystem 10. This feed or sender apparatus 18 comprises, in general, abase cabinet member or housing 452 supported on the floor 46, the sameas is the support frame 40 for the rotable member 14. This cabinet isprovided with a horizontally disposed top member having a planar surface454 above which is provided a horizontally disposed annular-shapedindexing table 456. This table is operatively connected to an indexerfor rotation in clockwise fashion looking down at the table from above.The indexer is generally referred to by reference numeral 458 (FIG. 13)and is fixedly located inside the cabinet member 452, as hereinaftermore fully described. The indexing table 456, as is best shown in FIG. 9of the drawing, has a horizontally disposed planar top surface 460parallel to the top planar surface 454 of the cabinet on which isprovided a plurality of, in this case 5, upwardly extending equallyspaced-apart protrusions identified generally by reference numeral 462(FIG. 10). In removable association with each protrusion 462 there isprovided a support means 464 for holding and supporting a verticallydisposed upright stack 466 of a plurality of compact discs 12 superposedone above the other in horizontal planes parallel one to the other andto the top planar surface 460 of the indexing table 456. The support orstacking means 464, as best seen in FIG. 10, comprises a circular-shapedstacking base plate 468 having a top portion defining a planarhorizontally disposed top surface 470 of a predetermined diameterapproximately that of a compact disc parallel to a bottom planar surface472. Extending vertically downwardly from horizontally disposed bottomsurface 472 is an annular-shaped bottom portion defined by an uprightperipheral outside edge 474 defined by a circle having a somewhat lesserpredetermined diameter than the peripheral edge of the top portion, asshown in FIG. 10. The inside diameter of the annular-shaped bottomportion defines an upwardly extending circular-shaped bore or well 476concentric with the circular-shaped top surface 470. This well 476 isdefined by a planar top surface 478 and upright peripheral edge 480. Theprotrusion 462 intrudes into well 476 and maintains the stacking supportmeans 464 in its desired location on the indexing table. The outsidediameter of the protrusion 462, and the diameter of well 476 shouldprovide a close fit. Moreover, the protrusion 462 should be of suchheight above the top surface of the index table, and the well 476 shouldbe correspondingly deep enough, to provide vertical stability to thestacking support member.

The top portion of the baseplate 468 is provided with a circular-shapedcentrally located opening 482 that communicates with, and is concentricto the well 476, the reason for which will be obvious from the drawing.Extending vertically upwardly and perpendicular to the top surface 470is an elongated circular-shaped spindle 484 fixedly secured at itsbottom end to the base plate or member 468 by a conventional threadedfastener 486 according to usual manner. The spindle 484 is provided witha rounded top 488 as shown in FIG. 10 and is of a diameter only slightlyless than the diameter of the centrally located circular-shaped opening212 provided in a compact disc 12. Thus, the compact discs will,importantly, have their outer circular-shaped edges in verticalalignment in the stack the surface bearing the recording facingdownwardly. The spindle 484 is of a somewhat lesser diameter at thebottom end intruding into the opening 482 providing a horizontallydisposed shoulder in contact with the upper surface 470 of the basemember thereby providing better stability and ensuring the verticallyupright orientation of the spindle 484.

Slidably engaged with the spindle 484 is a bobbin 487 having parallelplanar horizontally disposed top and bottom surfaces 490, 492 located inplanes parallel to the horizontal plane defined by the top surface 460of the indexing table 456. The bobbin 488, as seen in FIG. 10, isfurther defined by annular-shaped top and bottom portions 494, 496defined by the top and bottom surfaces 490, 492 and an integral,concentric, annular-shaped portion 498, the outer diameter of which issomewhat larger than that of the top and bottom portions, locatedintermediate to the top and bottom portion. The inner diameters of theannular-shaped portions defining the bobbin 487 are the same defining acontinuous, vertically disposed, circular-shaped opening through whichthe spindle 484 passes. These inner diameters are only slightly largerthan the diameter of the spindle, e.g. the same diameter as the centerhole 212 of a compact disc, so that the bobbin 487 will fit closely withthe spindle for purposes of stability yet be slidably engaged therewith,the reason for which will soon be disclosed. The bobbin 487, as shown inFIG. 6, has top and bottom portions 494 and 496 that are asymmetrical,i.e., the top portion is of a somewhat lesser vertical height than thebottom portion. This is of no concern to the general concepts of theinvention but in the particular embodiment disclosed need be taken intoconsideration. There is no reason, however, why these portions cannot beof equal height provided the horizontal disposition of the fork member,as later described, is taken into consideration.

As shown in FIG. 9, five stacks of compact discs 12 are provided on theindexing table 456, the spindles 484 of each defining a circular-shapedpath of travel concentric to the center defining the annular-shapedtable. The circular-shaped protrusion 462, as will be appreciated, isfunctionally the extension of the spindle in each of the stacks. Theseprotrusions 462 are so located that the centers of each lies at thecross-section formed by a radius of the circle defined by the outer edgeof the index table and the circle defined by the path of travel of thecenter point of the stacks of compact discs. The protrusions 462 areequally spaced-apart from one another their centers being located 72degrees apart in the sending apparatus 18 used in the practice of thisinvention. Thus, there are five fixed locations defined by thecircular-defined path of travel, such locations being separate anddistinct from the indexing table 456. Location No. 1, i.e. the loadinglocation or "load station", is the location from which discs 12 arepicked up from the sending apparatus and transferred, hereinafter morefully disclosed, one-at-a-time by the loading mechanism 336, andthereafter loaded onto the disc fixtures 108 present at location No. 1defined by the rotatable member 14, earlier described. The stations onthe sending apparatus are identified in clockwise manner, as earlierdescribed, station No. 1 being that station located at the bottom of thefigure shown and directly in front of the viewer, e.g., at the 6th hourof a clock (FIG. 9). Station No. 2 is the next adjacent station fromStation No. 1, in clockwise fashion, followed by Stations 3, 4, 5. The5th indexing station, i.e., the "pre-load station", is located nextadjacent station No 1, in counterclockwise manner. Nevertheless, agreater or lesser number of locations and stacks of compact discs 12 canbe provided for, as desired, depending somewhat upon the desireddiameter of the indexing table 456 to be used, as well as upon thedesired spacing between each of the stacking posts 462. In such a caseit may also be necessary to use a different indexer 458 than that usedin the practice of this invention, as hereinafter more fully described.Nevertheless, whatever the indexer used, the stacking posts 462 andsupport members 464 must be so located on the indexing table 456 as tobe spaced equidistant from one another, the center of the base member ofeach stacking member 464, as earlier disclosed, being located on anddefining a circle concentric to that of the circular-shaped indexingtable. The stacks of discs 12 will desirably be located inwardly fromthe circumferential edge of the indexing table so that the edges of thecompact discs 12 will not stick out from that edge.

Located centrally of the index table 456 and extending verticallyupwardly from the circular-shaped opening 604 in the index table 456 isan elevator means or mechanism 500 for elevating a predetermined stack466 of compact discs located at Station No. 1, i.e. the load station, toa specific predetermined height vertically above the index table, ashereinafter more fully described. When raised to that predeterminedheight, the loading mechanism 336 will be able to pick up the nextcompact disc 12 on the top of the stack of discs then being loaded,i.e., the top-most disc, and to transfer that disc 12 and load it ontothe transport member 14 of the printing system. The elevator mechanism500 comprises, as will be somewhat better appreciated by reference toFIG. 10, along with FIG. 9, a vertically disposed elongatedcircular-shaped housing or supporting member 502. The housing 502 has atop end 504 and a bottom end 506 (See FIG. 13). The housing member 502is further defined by an open front 508 defined by the inner ends ofvertically upright, spaced-apart, elongated planar edges 510, 512located in the same vertical plane parallel to that of the front edge451 of the cabinet 452. These planar front edges, at their inner ends,define an internal, elongated, vertically disposed cavity 514 havingapproximately the shape of a rectangle, as best seen in FIG. 9. Thecavity 514 is defined by a vertically upright planar back surface 516which is perpendicular to and intersects with the parallel, planarupright spaced-apart side walls 518, 520, and the vertically uprightinner ends of the front edges 510, 512, defining the open front of thecavity. The planar side walls 518, 520 defining the cavity 514 arelocated equidistant from an imaginary vertically disposed plane dividingin half the planar back surface 516 parallel to side walls 518, 520 andpassing through the center defined by the circular-shaped housing 502.

Provided in the sidewalls 518, 520 are vertically disposedrectangular-shaped elongated grooves 522, 524, respectively, thesegrooves being perpendicular to the said planar top and bottomhorizontally disposed parallel ends 504, 506 of the supportingstructure. The grooves 522, 524 are so located in the respectivesidewalls as to be in direct opposition to one another and are bisectedby a vertically disposed imaginary plane perpendicular to the sidewalls518, 520 and passing through the center defined by the circular shapedsupport member. Located within the respective grooves 522, 524 are upperand lower pairs of rotatable guide wheels 526, 528, 530, 532 (FIG. 11).These guide wheels are mounted for rotation e.g., on axles 527, 529,531, and 533, in conventional manner on the vertically disposedelongated body member 534 of the fork carriage assembly identifiedgenerally by reference numeral 536 (see FIG. 10). As shown more clearlyin FIG. 11, the upper and lower pairs of guide wheels, respectively, arelocated in direct opposition to one another in the vertically uprightguides 522, 524. Thus, the guide wheels provide means for guiding thefork carriage assembly 536 in a vertical up and down motion, as latermore fully described.

The fork carriage assembly 536 comprises a vertically upright forksupport member 538 comprising two spaced-apart upright parallel supportelements 540, 542, each being defined by a top end and a bottom end. Tothe bottom ends of the fork support member 538 there is fixedlyconnected a horizontally disposed fork member 544 perpendicular to theupright support elements. The fork member 544 comprises, as is shownsomewhat more clearly in FIG. 9, two spaced-apart elongated legs 546,548 defined by outer and inner parallel longitudinal edges 550, 552, and554, 556, respectively, and front end edges 558, 560 perpendicular tothe outer edges. The inner edges 552, 556 of the legs are shorter thanthe outer edges 550, 554 and connect with the inner ends of the endedges 558, 560 defining smooth curved inner edges 559, 561. The curvedend edges 559, 561 define a semi-circle (FIG. 9) that conforms to theouter circumferential surface of the bottom portion of theannular-shaped bobbin, as shown in the drawings, when the fork is inoperative engagement to raise a stack of discs. As seen in FIG. 9, theend edges 558, 560, in the more preferred aspect of the invention, lieon an imaginary line parallel to the upright member of the carriage andwhich passes through the center of the circle defined by theannular-shaped bobbin. The legs 546, 548, as will be appreciated, can besomewhat longer than shown in FIG. 9, provided the curved surfaces 559,561 do not continue to curve at their respective outer ends but,instead, define a linear edge parallel to the outer edges of the forkmembers. The legs can even be somewhat shorter, if desired. This is lesspreferred, however, as it affords less stability to the stack of compactdiscs as such is being raised.

Extending to the rear and perpendicular to the back planar verticallydisposed surfaces 562, 564 of the upright fork support members 540, 542,respectively, are provided conventional linear bearing rods 566, 568.These rods are of equal length and spaced-apart from one another in thesame horizontal plane, parallel to the plane defined by the top surfacesof the fork legs and are fixedly secured at their front ends to theupright fork support members. The rearward free ends of the bearing rods566, 568 are located in conventional linear bearings 570, 572 providedin horizontally disposed circular-shaped, spaced-apart elongatedopenings (not shown) provided at the bottom end of the carriage bodymember 534 and extending inwardly from the vertically disposed planarsurface 574. Thus, when the fork assembly 538 is caused to move in aback-and-forth horizontal direction, as later more fully described, thebearing rods 566, 568 will be supported for reciprocal movement back andforth in the bearings 570, 572, respectively.

At the top end of the upright support member 540 is pivotably connectedone end of an elongated horizontally disposed link 576. The other end ofthe link is pivotably connected to a threaded member or nut identifiedby reference numeral 578 having a centrally disposed circular-shapedopening 580 provided with an internal thread pattern (not shown). Thisthreaded member is in the general shape of an isosceles triangle (seeFIG. 9) defined by the base 582 and the equal sides 584, 586.Nevertheless, the apex, i.e., where the sides intersect, is rounded off,as shown in the drawing. And, the two sides and base are shortenedproviding flat ends as shown. Thus, the threaded member can be providedin a compact space and rotated in clockwise and counterclockwise mannerin a horizontally disposed plane parallel to the plane defined by thetop surfaces of the fork legs 546, 548, as later disclosed. Thecounter-clockwise rotation of threaded member 578 is limited by ahorizontally disposed stop member 588, the purpose for which will soonbe disclosed. As will be readily appreciated by those in the art, thethreaded member 578 need not necessarily be of the same configuration asspecifically shown in the drawings, provided such performs the necessaryfunctions for such a member as disclosed hereinafter. The shape and sizeof the threaded member will depend, among other things, upon therelative sizes of the cavity 514, the fork carriage assembly 536, thelength of the link 576, the length of the bearing rods, etc. The lengthof the bearing rods 566, 568 can vary somewhat, depending upon thelength of the fork legs 546, 548, the length that such legs must travel,i.e. be retracted, to clear the bottom portion of the bobbin, etc. Theoptimum length of the bearing rods 566, 568 in any particular case, andthe size and dimensions of the threaded member 578 can readily bedetermined by a skilled artisan. Importantly, the fork member must beretracted a sufficient distance to clear the bottom portion of thebobbin, as above disclosed; otherwise, the fork member will interferewith the rotation of the indexing table and the indexing of a stack intothe loading position.

Located in and passing through the opening 580 in the threaded member isa vertically upright circular-shaped, elongated, rotatable member orscrew 590 on the surface of which is provided an elongated threadpattern 592, matching with that provided in the opening of the threadedmember or nut 578. Thus, as later more fully described, on rotation ofthe elongated screw member 590, the nut 578 will be caused to move up ordown, depending upon the direction of rotation of the screw member andthe friction between the two. The threaded member and screw should eachbe, most desirably, manufactured of materials having good frictionalcharacteristics, allowing the screw to readily rotate in the threadedmember, as hereinafter more fully disclosed. In the practice of theinvention, the threaded member was of stainless steel. The screw was ametal screw coated with a layer of Teflon polytetrafluroethyleneaccording to usual manner. The threaded member and screw can each beprovided of other materials, if desired, e.g., a plastic material havinglow frictional characteristics such as DELRIN polyacetal resin.Nevertheless, no matter what the materials of construction of thesecomponents, the friction between the two must be capable of adjustmentlater more fully disclosed.

The screw member 590 is clear of the thread pattern at its ends, the topend thereof being rotably located in usual manner in a conventionalthrust bearing 594 located in the horizontally disposed supportingstructure 596 fixedly secured in the internal cavity 514 to housing 502.The bottom end of the screw member 590 is operatively connected forreversible rotation, clockwise and counterclockwise, as desired, to thedrive shaft 598 of a conventional reversible stepping motor by couplingmeans 602, according to usual techniques (FIG. 13).

As seen in FIG. 13 of the drawing, the bottom portion of the housing orsupporting structure 502 extends vertically downwardly and passesthrough the circular-shaped centrally disposed opening 604 provided inthe indexing table 456. The planar bottom of the housing 502 rests uponand is fixedly secured to a fixed support member 606 having an upperhorizontally disposed annular-shaped planar surface 608. This supportsurface is parallel to the planar top surface 456 of the indexing table.The support member 606 is centrally located, the annular-shaped topsurface 608 thereof being concentric with the circular-shaped opening610 provided in the top 454 of the cabinet 452 and the opening 604provided in the indexing table 456. The horizontally disposed planarbottom surface 612 of the support member rests upon the horizontallydisposed top planar surface 614 of the support platform 616. The topplanar surface 614 is parallel to the top surface 454 of the cabinet.Although not shown in the drawing, the support platform 616 is fixedlyconnected according to usual technique to supporting framework locatedwithin the cabinet 452. Stepping motor 600 is located directly beneathplatform 616 and in contact with its bottom surface 618. The steppingmotor is connected to the platform and support member 606 by means of aplurality of conventional threaded fasteners such as indicated byreference numeral 620. This is readily accomplished according to usualtechnique. Various stepping motors may be found suitable in the practiceof the invention. One such a motor which has provided satisfactoryresults is manufactured by Compumotor Div., Parker Hannifin Corporation,Rohnest Park, Calif. and sold under the trade designation PK 3-83-93.This motor is characterized by an output torque 150 in./ounces, a topspeed of 300 rev./min. and by fast start/stop characteristics withramping aspect. It needs of course to be reversible, i.e., capable ofrotating the screw 590 in clockwise direction and then reversing itself,rotating the screw in counterclockwise direction, as hereinafter furtherdisclosed.

Turning now to FIGS. 10, 12, it will be seen that midway between thespaced-apart sidewalls 518, 520 is a vertically upright, elongatedrectangular-shaped clamp activating member or clamp bar 622 defined byparallel planar faces 624, 626. The clamp bar 622 is so located withinthe cavity 514 as to be perpendicular to back wall 516 and equidistantfrom the parallel sidewalls. The bottom end of the clamp activatingmember 622 is pivotably connected to the back edge of the elongatedhorizontally disposed clamp member 628. This clamp member is defined byplanar top and bottom surfaces 630, 632 the width of which at the frontend is defined by longitudinal parallel side edges 634, 636 (FIG. 9).The clamp member 628 in its rest position, i.e., when the fork carriageassembly is located at the bottom of its travel, is perpendicular to theback side 516 of the cavity and terminates at its front edge 638perpendicular to the side edges 518, 520. The clamp member 628 ispivotally mounted at a suitable point between its ends for up and downmovement by means of downwardly protruding mounting flanges 640, 642.Connecting the mounting flanges together and to a fixed pivot supportmember 644 is the elongated mounting pin 646 which extends transverselyto the sidewalls 518, 520 and parallel to the back wall 516. This pivotsupport member is upwardly extending and fixedly secured to ahorizontally disposed frame member 648 fixedly secured within the cavity514 in the bottom portion thereof opposite the spindle base or supportmember 464. Thus, when the clamp bar 622 is moved in a vertically up anddown motion, the clamp member 628 will be caused to move in an up anddown fashion by means of the pivot mounting pin 646. At the front edgeof the clamp member 628 and fixedly secured thereto is a downwardlyprotruding member 650 which terminates in a bottom planar face. Thisface, as seen in FIG. 10, engages the top planar surface 470 of thestacking base plate 468, the reason for which will be hereinafterdisclosed. The clamp bar 622 is provided at its top end with anelongated vertically disposed slot 652 in which is located ahorizontally disposed pin 654 the ends of which are fixed (not shown) inthe supporting structure 596 in conventional manner. This pin isprovided perpendicular to the clamp bar or activating member 622 and inparallel disposition to the back wall 516 of the housing. Thus, theactivating member can move a limited distance vertically up and down, asdesired, the reason for which will soon be disclosed. The length of theslot 654 should be sufficient to allow the clamp bar 622 to move freelyup and down to the extent desired. The extent of the movement up anddown of the clamp bar 622 will be determined by conventional stopmembers 656, 658 located in opposition to one another and above andbelow the clamp member 628. The bottom end of each of these stop membersis located in a threaded bore provided in the frame member 648 accordingto conventional techniques. The stop members are each adjustable inusual fashion, as desired, so as to provide the other end thereof nearerto or farther away from the top and bottom surfaces 630, 632.

Extending perpendicularly outwardly from the back side of the carriageassembly body member 534 are spaced-apart drag members 660, 662 definedby opposed planar, parallel vertically disposed spaced-apart surfaces664, 666, respectively. These drag members are provided withcircular-shaped, horizontally disposed bores 668, 670, respectively.These bores extend inwardly from the respective outer planar, verticallydisposed surfaces 672, 674, parallel to surfaces 664 and communicatewith the horizontally disposed bores 676, 678 having a circular shapebut of somewhat lesser diameter. In the bores 668, 670 are providedelongated coiled springs 680, 682, respectively, the respective outerends of which are located in dead bores provided (not shown) incircular-shaped plug members 684, 686. These members, if desired, can beprovided so as to be adjustable in and out of the bores in which each islocated, e.g., by providing matching thread patterns on the matingsurfaces according to conventional techniques. Thus, in this waysomewhat greater or less tension can be provided in the coiled springsso as to provide a greater or lesser force, as desired, against thesides 624, 626 of the clamp bar, the purpose for which will soon be madeknown. The inner ends of the springs are located in dead bores providedin circular-shaped members 688, 690 such as indicated by the dead bore692 provided in member 690. The members 688, 690 each have a diametersomewhat less than the respective bores in which they are located so asto be slidable therein. The outer ends of the members 688, 690 telescopeinto respective bores 668, 670, as indicated in the drawing (FIG. 12).The members 688, 690 are provided with vertically disposed planar faces694, 696 respectively, which press against and frictionally engage theopposing planar faces 624, 626 of the clamp activating member 622. As aresult, the members 688, 690 provide a braking action or drag on theupward and downward movement of the fork carriage assembly 536. Thebraking members 688, 690 can be provided of various materials providedthe clamp activating member can slide therebetween, as desired. Thesprings in combination with the brake members should provide enoughforce against the clamp activating member as to cause the clampactivating member 622 to be pulled slidably upwardly with the upwardtravel of the fork carriage assembly as hereinafter later described.

It will be appreciated that as the clamp activating member 622 movesupwardly, the clamp member 628 is caused to pivot from the horizontalposition downwardly at its front edge. Thus, the downward protrudingmember 650 presses against the top surface 470 of the base plate member468 providing a downward force against and preventing the stacking baseplate 468 from moving upwardly along with the fork carriage assembly 536during the raising of the stack 466 of compact discs 12 upwardly. Thus,the stacking base plate 468 is caused to remain on the index table 456and seated on its post 462. This is an important feature of theinvention, particularly where a large number of compact discs 12 may belocated on the spindle 484, due to the close tolerances between thespindle diameter and the diameter of the centrally located openings 212in the compact discs. Without a downward force being applied against thestacking base plate 468, as above disclosed, the compact discs 12 cannotbe readily stripped from, sometimes not at all, the spindle 484, as thefork carriage assembly is raised vertically upwardly. This results fromthe frictional engagement between the spindle periphery and theperiphery of the center hole of the compact discs causing the baseplate, spindle and stack of compact discs to move as a unit, rather thanallowing the compact discs to slide upwardly on the spindle 488 and tobe separated therefrom, along with the bobbin 488 later more fullydescribed. The movement up and down of the front edge of the clamp islimited by means of the stop members or adjusting screws 656, 658located above and below the clamp member.

Provided at the top end of the main supporting structure, i.e., housing502, and fixedly secured in the horizontal support member 596 there isprovided in a predetermined forward location a conventional fiber opticsensor assembly 698 comprising a diffuse-reflective fiber optic sensor700. Such a sensor is commercially available from Effector, Inc. ofEaston, Pa. This sensor, in general, functions to detect the presence ofa compact disc 12 at a predetermined height. This height is determinedlargely by the length of the housing 502 extending vertically above thefloor or the index table 456, as desired. The sensor assembly 698 ismounted so as to be adjustable vertically upwardly or downwardly wherebyany final adjustment can be made so that the optical fiber sensor 700will be positioned directly opposite to the topmost compact disc 12, asshown in FIG. 10, when the stack of compact discs is first raisedupwardly to the height desired. Then, as that topmost disc is picked upand transferred to dial 14, the fiber optic sensor detects the absenceof a disc 12 at that set height, causing the stack of discs to be raisedincrementally so that the next disc in the stack, i.e., the now topmostdisc, is sensed by the sensor 700 and the fork carriage assembly stops,momentarily, its upward movement. The optical fiber sensor is capable ofalso functioning as a counter. Thus, the sensor mounted on the receivingapparatus 20 counts the number of discs stacked on a spindle, determineswhen such spindle has the predetermined number of discs thereon, andcauses the indexer associated with that apparatus to index an emptyspindle into the loading position. The predetermined height to which thestack of compact discs 12 is raised by the elevator mechanism 500 mustbe such as to allow the loading mechanism 336 to pick-up the topmostcompact disc and transfer it to the loading station. Thus, it will benecessary, as will be appreciated by those skilled in the art, tocoordinate, in particular, the vertical lengths of the housing 502 andthe housing 224 of the loading/unloading mechanism, and the distancethat the loading mechanism moves up and down.

Referring now again to FIGS. 10, 11, there is shown in operativecombination with the elongated screw 590 an anti-backlash nut orfriction adjusting means indicated generally by reference numeral 702,for removing excessive end play in the threaded member 578 and toprovide the desired interference in the threaded interface between thescrew and threaded member 578. The adjusting means 702 is commerciallyavailable and well known to those skilled in the art. In general such ameans comprises an elongated vertically disposed annular-shaped bushing704 having an outside thread pattern (not shown) that engages with theinner thread pattern (not shown) provided in the horizontally disposedflange member 706 extending forwardly from the carriage body member 534of the fork carriage assembly 536 at its top end. Located below theflange member 706 is an elongated cylindrical shaped spacer element 708having a top horizontally disposed annular-shaped end 710 in contactwith the horizontally disposed bottom end 712 of threaded bushing 704.The horizontally disposed bottom end 714 of the spacer element, parallelto bottom end 712, is in contact with the horizontally disposed, topplanar surface 716 of the threaded member 578. Thus, by turning thethreaded bushing 704 more or less play will be provided between the forkcarriage assembly 536 and the threaded member 578 through which theelongated screw 590 passes and with which it is operatively engaged.Importantly also, the adjusting means allows adjustment of thefrictional interface, as above-alluded to, allowing control over the inand out movement of the fork member 540. Once the bushing 704 isadjusted, as desired, any unintended loosening thereof resulting inexcessive play between the carriage assembly and threaded member 578 canbe prevented by a conventional locking nut 718 in usual manner. Thus,the threaded member 578 is captured axially on the elongated screw 590relative to the fork carriage assembly. It will be appreciated that theinternal dimensions of the elongated openings in the bushing and spacerelement and in the centrally disposed opening (not shown) in the lockingnut 718 must be such as to be out of contact with the thread pattern 592provided on the screw 590. The length of the spacer element 708 willdepend somewhat upon the vertical distance on the carriage assemblybetween the flange 706 and threaded member 578. In any event, the lengththereof, in combination with the bushing 704, need be such as to take upany slack and provide control of the friction interface, as earlierdescribed.

Turning now to FIG. 13, it will be seen that the rotatableannular-shaped indexing table 456 is fixedly secured to and mounted onthe rotatable member or ring bearing support 720 using conventionalmeans such as threaded fasteners indicated generally by referencenumeral 722. Thus, access to other functions hereinafter described ispossible through the center opening of the table. The rotatable member720 is of a somewhat annular-shape conforming to the shape of the fixedsupport member 606 which resides internally of the rotatable member 720and centrally disposed therein, as shown in the drawing. Between theouter circumference of the top portion of the fixed support member 606and the inner circumference of the top portion of the rotatable member720 there is provided an annular-shaped bearing member 724 in usualmanner. The bottom circular-shaped outer portion of the rotatable member720 is provided according to usual technique with a horizontallydisposed pulley means 726 around which rides one end of the horizontallydisposed timing belt 728, the other end riding around the pulley 730located on the output drive shaft 732 of the indexer 458. Thus, theindexing table 456 is driven by the indexer 458, a conventionalthree-stop indexer. Various such mechanical indexers commerciallyavailable can be used in the practice of the invention provided such isthree-stop and has a dwell index ratio of 180 degrees. The indexer usedin the invention is available from Camco Custom Cams, earlier disclosed,under the trade designation RG30. The input drive shaft 734 of indexer458 is provided with a pulley 736 over which rides one end of a drivebelt 738, the other end riding over the pulley 740 located on the driveshaft 742 of the variable speed motor 744. A motor found to providesatisfactory results in the practice of the invention is available fromMinaribe Electric Co. of Glendale, Calif. Nevertheless, in general, anymotor having a parallel shaft, helical gear and is a permanent magnetD.C. motor will be found satisfactory provided it produces the necessarytorque. Whatever motor is selected, however, should be capable ofvariable speed, and have suitable speed range to accomplish the purposefor which it is intended. The selection of a suitable motor is wellwithin the skill of the art. As usual, the motor can be torque limitedto prevent damage in the event of a jam by association with aconventional controller. Thus, the indexer 458 will provide the desiredtorque and rotation to the indexing table 456 and cause the stacks ofcompact discs provided thereon to each index in sequence to theappropriate location, as hereinafter further described. As earlierdisclosed, the indexer 458 used is a three stop indexer. Accordingly,the ratio of the diameters of the driving and driven pulleys, i.e.,between the diameter of pulley 720 and 726, need be such as to convertthe three stop motion to the five stop motion capability of the indexingtable 456. The selection of pulleys of the most appropriate diameter iswell within the skill of those in the art.

Turning now to FIG. 8, it will be seen that, in the embodiment shown inthat figure, contrary to that shown in FIG. 10, stack spacing means 746are provided for use in the handling of short stacks of compact discs12, i.e., stacks of a lesser number of discs therein than generallyprovided for in the operation of the particular loading andsending/receiving apparatus. This is of particular concern as theloading/unloading mechanisms, and the elevator mechanism are, ingeneral, designed and constructed to pick up the topmost compact disc ina stack at a certain predetermined height and to provide such a disc atthat height, respectively. And, moreover, as a result, the sensorlocation for sensor assembly 698 is also somewhat predetermined and thesensor 700 can be positioned and repositioned upwardly and downwardlyonly to a limited extent. Thus, in the construction of the elevatormechanism, one should keep in mind not only the predetermined verticaldistance that the stack of compact discs is to be raised, but also thelimited vertical movement of the loading mechanism. Thus, the maximumnumber of compact discs 12 that are to be provided in any particularstack will be first determined. In the practice of the invention, themaximum number of discs to be provided in a stack has been set as apractical limit at 200 discs. And, the predetermined height for locationof the topmost disc sensor 698 has been set with that in mind, alongwith the limitations on the vertical up and down movement of the loadingmechanism and the height of the elevator mechanism, i.e., the maximumextent that the fork carriage assembly is to move vertically upwardly.This predetermined height has been arbitrarily set at a nominal heightof 40 inches above the floor. Thus, when stacks of a lesser number ofcompact discs are desired, or necessary because of the remaining numberof discs to be printed in any particular run, e.g., a 100 compact discstack, rather than a stack of 200 discs, a stack spacing means 746 mostdesirably is used to prevent wasted travel of the fork carriageassembly, travel time, etc. and to provide a more efficient operation.The stack spacing means 746 used in such a case, as shown in FIG. 8, isan elongated member having generally an I-shaped cross-section and topand bottom parallel planar surfaces. Although not shown in the drawing,the top surface will be provided with an upwardly extending protrusionlike protrusion 462 provided on the annular-shaped index table 456. See,for example, FIG. 10. And, the bottom surface of the spacing means willbe provided with an upwardly extending well such as the well 476provided in stacking base plate 468. Thus, the spacing means 746 will beretained in place on the rotatable index table, and the stacking means464 on the top of the spacing means. It is necessary, of course, thatthe protrusion and well provided on and in the spacing means beconcentric with one another. Spacing means of various heights can beused in the practice of the invention, dependent upon the desiredminimum number of discs in a stack and upon the height of the spindle.

In operation of the 3-color silk-screen printing system disclosed inthis application, the compact discs 12 to be printed are loaded onto aplurality of stacking means 464. Each spindle 484, as disclosed herein,will accommodate a stack of 200 compact discs, without the presence ofthe spacer. In this case the spindles have a height of about 14.8inches, and the bobbin height is about 0.7 inches. This leaves the topabout 14.1 inches of the spindle free for stacking the compact discs.The loaded spindles are then each placed on the indexing table 456 ofthe automatic feed means 18. This loading is made in a counterclockwisefashion, loading the first spindle onto the indexing table at thelocation next adjacent the pre-load station. No stacking means areprovided at the load and preload stations on the indexing table. Thepre-load station is the station just prior to the load station, movingin counterclockwise fashion. The load station is the station locateddirectly in front of the fork member of the fork carriage assembly. SeeFIG. 9. It is important that such manner of loading occurs, particularlyif the number of compact discs to be printed, or the remaining number inany particular printing operation, is insufficient to provide loadedspindles for all the spindle posts. As earlier disclosed, with the stackspacer on a spindle, the system can operate with only 100 compact discson the spindle, not 200. The spacer used in this case will have a heightof about 6.44 inches. Thus, in some cases where there may be fewercompact discs 12 to be printed at any one time, it may be desirable toprovide stack spacers on each of the stacking posts or protrusion 462,or at least on one or more of them. With appropriate use of spacers andspacers of the desired height, the number of compact discs 12 to beaccommodated on the index table can vary somewhat.

When the automatic feed means 18 has been loaded as above-disclosed, itis then moved into position, if such is a free standing unit, as shownin FIG. 1. Thus, the feed means is moved closely adjacent the transportmember 14 so that the protrusion 462 on the feed means index table atthe load station is located directly under a sucker, e.g., the sucker430 on sucker arm 418. The sucker arm 414, in this case, will locate thesucker 426 directly above the disc fixture 108 at station No. 1 on thetransport member. The correct positioning of such can readily bedetermined by eye. Nevertheless, if desired, docking features such asrails on the floor adjacent the loading/unloading apparatus 16 can beprovided, according to conventional technique. Also, if desired, theautomatic feed apparatus 18 can be fixedly connected to the frame 40 soas to always be in the correct location relative to the rotatabletransport member 14 and loading/unloading apparatus 16. It is importantwhere the automatic feed means 18 is a detached unit that such beinitially oriented relative to the load/unload apparatus 16 that thefeed apparatus is in operative association with and properly locatedunder the loading mechanism 336 of the loading/unloading apparatus.Thus, the stack of discs in the location next adjacent the pre-loadposition counterclockwise will be properly located so as to be indexedinto the pre-load position and subsequently into the load position, aslater somewhat more fully disclosed.

In similar manner, the receiving apparatus 20 (FIG. 1) will be locatedrelative to the unloading mechanism of the loading/unloading apparatus.The receiving apparatus is of similar construction as the feed apparatus18, earlier disclosed. This apparatus does not, however, require thedisc elevator mechanism earlier described. Thus, the receiving apparatus20 comprises, in general, only the combination of the stacking means andindexing apparatus. The printed compact discs 12' are each removed,one-at-a-time, from the transport means by the unloading mechanism andthen are dropped onto a spindle at the unload (load) station. Thus, inpositioning the receiving apparatus 20 relative to the unloadingmechanism, it is necessary that a sucker cup be located directly abovethe centerhole provided in the disc fixture located at station No. 21.With such orientation, the next adjacent sucker clockwise will belocated directly above a stacking means in the unload position, as shownin FIG. 1 of the drawing.

When the stacking means at the unload position on the receivingapparatus is full, i.e., provided with a stack of compact discs of thedesired number, the indexer indexes that stacking means in clockwisemanner to the next location for removal by the operator of the stack ofprinted discs from the indexer table. The printed compacted discs aresubsequently removed from the stacking means for further handling, asdesired. An optical fiber sensor assembly, as earlier disclosed, isprovided on the receiving apparatus to determine when the stacking meansis full. This sensor assembly can be mounted on the housing 502 (notshown on the receiver apparatus) or elsewhere as desired. At the sametime, the empty spindle located at the pre-unload (pre-load) location iscaused by the sensor to index into the unload location. Rather thanproviding distinct apparatus for the sending and receiving of compactdiscs, as above-disclosed, like apparatus can be used for bothfunctions, if desired, with some temporary modification. Nevertheless,if like apparatus is used both for the feeding of compact discs to theloader/unloader apparatus and for receiving of compact discs 12'therefrom, the elevator mechanism 500 can be removed except for thehousing 502 or deactivated, as desired, and left in place. Thisdeactivation can be readily accomplished most preferably by a programelectronically, according to conventional techniques, to disconnect theelevator circuit. Nevertheless, this could also be accomplished byuncoupling the screw 590 from the drive means for this member, asdisclosed earlier herein.

Once the feed and receiver apparatus are located in position, thevertical height of each such apparatus, relative to theloading/unloading apparatus, can then be adjusted, if needed. This isreadily accomplished by height and leveling adjusting screws provided onthe base of the cabinet housing the indexer, according to usualtechnique. The system is then ready to be activated for the particularcompact disc printing operation at hand. Thus, the cycle button on thecontrol panel is pushed, causing the system and its various componentsto be placed in the starting mode. At that time, two optical sensors asearlier disclosed, provided at the pre-load position in suitablelocation, monitor the presence of a non-empty spindle, i.e., it at leasthas one compact disc thereon, the orientation of a bobbin, and thepresence of a "misplaced" bobbin. A misplaced bobbin is one in which thebobbin is not properly located on the spindle, e.g., the top surface ofthe bobbin is not actually horizontally disposed and parallel relativeto the top surface of the index table. By orientation of the bobbin,such must be so located that the short side thereof is the top portion,as shown in FIG. 10. It will be noted from that figure of the drawingthat the top and bottom portions are asymmetrical, a characteristic inthe bobbins used, as obtained from the manufacturers of the stackingmeans, a conventional unit commercially available. This orientation isrequired due to the built in characteristics and home location for thefork member. Nevertheless, there is no reason why symmetrical bobbinscannot be used provided such has been taken into consideration in thedesign of the elevator mechanism. If an empty stacking means isdetected, the system will treat the stacking means as "no good" and thefeed apparatus will not attempt to send compact discs from this stackingmeans. The indexer 458 will then index the the next adjacent stackingmeans counterclockwise into the pre-load location, at the same timeindexing the stacking means in the pre-load station into the loadposition. The optical sensors in the preload position once againdetermine whether a "good" stacking means is present at that position.If a good stacking means is detected, the indexer then indexes thatstacking means into the load position. The "no good" spindle previouslyin the load position is indexed to the next station clockwise forremoval and replacement with a stacking means having a stack of discs ofthe desired number, properly oriented bobbin, etc. In the event, anon-empty spindle and good bobbin is detected at the pre-load position,and a good bobbin is already present at the load position, the systemwill then "remember" the good stacking means and spindle until such timethat the good stacking means is then indexed into the load position. Thecycle continues thusly until all the compact discs have been sent to theloading mechanism and transferred to the transport member for printing.If a good stacking means is not sensed after five attempts, the feedapparatus is programmed to shut itself off. The remainder of theprinting system, however, remains in operation and does not stop unlessthere is no place to stack a printed compact disc, e.g., the stackingmeans on the receiver apparatus is full and for some reason has notindexed forward, allowing an empty stacking means to index into the loadposition.

On indexing of a good spindle into the load position on the feedapparatus 18, the stack of discs on that stacking means is automaticallyelevated by the elevator mechanism to the predetermined "send" position,i.e., the height vertically upwardly to meet the loading mechanism. Thissend position can be varied somewhat, if desired, by adjusting thevertical location of topmost disc right angle optical sensor 700 locatednear the top of the elevator mechanism, earlier described. The stack ofcompact discs 12 is lifted by the fork carriage assembly, the forkmember 544 of which extends under the bobbin on the spindle (FIG. 10).The fork member 544 is initially retracted as shown in FIG. 14 when thegood spindle indexes into the load position. When the command isreceived from the PLC, earlier disclosed, to lift the stack of compactdiscs 12 into position for pickup of the topmost disc by the loadingmechanism, the screw 590 is caused to rotate in a counter-clockwisedirection. The friction between the threaded member or nut 578 and thescrew 590 is used to drive the fork member 544 into position under thebobbin (FIG. 9). Once the fork member has been fully extended under thebobbin 488,as shown in FIG. 10, the rotation of the screw 590 in the nutstarts to lift the fork carriage assembly and stack of compact discs.This is made possible because the threaded member is prevented fromfurther counter-clockwise rotation by the stop 588. When the top mostdisc 12 reaches the predefined send position, i.e., it is sensed by theoptical fiber sensor 700, the fork carriage assembly will stop and holdits position until the top most disc 12 has been removed from the stackof discs by the loading mechanism hereinafter further described. Theelevator send speed can vary somewhat as desired. This will, in general,depend primarily upon the output of printed compact discs desired, orspeed at which the apparatus can operate, as will be readily appreciatedby those skilled in the art, as well as upon the dwell time of theelevator desired at the send position. The elevator speed in thepractice of the invention as disclosed herein has been optimally set atabout 90 rpm, i.e., the screw 590 rotates at that speed. In this case,when the top most disc 12 reaches the send position, the fork carriageassembly will stop and hold its position at that elevation until thedisc has been removed for a duration of about 0.25 seconds.

If the optical fiber sensor 700 does not detect a disc 12 on the spindle484, the elevator mechanism will continue its upward travel until asecond optical sensor (not shown) is reached, indicating to the forkcarriage assembly that it has reached the predetermined top of itsupward travel. This top of travel sensor is located above the sensor 700and inside the housing at the top thereof (not shown). Various sensorscan be used for this purpose provided such can function to detect thepredetermined extent of upward travel by the spindle, e.g., by detectingthe edge of the bobbin, or some portion on the fork carriage assembly,as desired. The optical sensor used in the practice of the invention fordetecting the top of travel of the elevator mechanism is like thatearlier disclosed. The providing of such a sensor is critical in thepractice of the invention so that the fork carriage assembly stops andreverses its direction of travel.

When the top of travel of the stacking means in the load position issensed, the screw 590 is caused to reverse its direction of rotation bythe stepping motor 600. The elevator mechanism then returns to its homeposition at an optimal rate of about 450 rpm. This location is definedby a conventional optical sensor, like that earlier disclosed. Thisoptical sensor (not shown) is located just inside the housing for theelevator mechanism in a suitable position, readily determined by thoseskilled in the art to importantly detect the down and home position ofthe fork carriage assembly, i.e., the fork member is retracted, as shownin FIG. 14. The screw 590 on reaching the down position neverthelesscontinues its rotation causing the nut to rotate in clockwise fashionand in so doing to retract the fork member 544 from its location underthe now empty spindle to its home position.

When the fork member is in its fully retracted location (FIG. 14 ), theempty spindle then indexes clockwise to the next adjacent location. Thespindle in the preload location at the same time indexes to the loadlocation. If the spindle from the preload position is a good spindle thecycle repeats, i.e., the fork carriage assembly is raised to thepredetermined send location, and the topmost compact disc in the stackis picked up by the loading mechanism, as before-described.

If during the course of feeding compact discs, the feed apparatus isremoved from the systems "cycle mode," the system will "remember" thatcompact discs are still present on the spindle at the load position ofthe feed apparatus. This assumes that there were compact discs on thespindle waiting to be sent to the loading mechanism at the time ofremoval of the feed apparatus from the operating cycle. When the feedapparatus is returned to the system's cycle mode, the fork carriageassembly will immediately attempt to feed compact discs once again fromthe spindle located at the send location without first requesting atable index. This memory will be cleared, however, when a manual indexis performed, the stack reset sensor is tripped, or there is a powerloss.

As the fork carriage assembly is being raised whereby the top-mostcompact disc can be detected, the loading/unloading apparatus 16 androtable support member 14 is placed in synchronous operation with thedisc sender apparatus 18. Thus, an empty sucker arm on the loadingmechanism is caused to rotate horizontally in clockwise fashion,stopping in the predetermined precise location in the horizontal planedescribed vertically above the spindle having a stack of compact discs12 in the load position. The unloading apparatus 20 is placed at thesame time in the operating cycle. Also, when the system cycle button ispushed, the transport member 14 is caused to rotate in clockwise manner,automatically indexing at each third position, as later more fullydescribed. Any final adjustments in the location of the feeding andreceiving apparatus relative to the loading/un-loading apparatus is madeat this time.

The horizontal rotation of the loading mechanism is stopped, placing asucker directly above the stack of discs in the load position on thefeed apparatus. The arm 278 on the loading mechanism 336 of theloading/unloading apparatus is then caused to pivot downwardly at itsouter end and the loading mechanism 336 drops vertically downwardly apredetermined distance putting the sucker cup in position for picking upthe top most compact disc 12 in the stack. The arm 278 is then caused topivot back to the horizontal causing the loading mechanism to be raisedthe desired predetermined height to clear the spindle on being rotatedin that horizontal plane. The pick and carry unit then rotates in thathorizontal plane transferring the top-most compact disc 12 from thestack of discs to the predetermined point vertically above the discfixture 108 located at position No. 1 on the transport member. The arm278 on the loading/unloading apparatus again pivots downwardly, asbefore, dropping the loading mechanism vertically downwardly to thepredetermined point just above the disc fixture. It will be appreciatedthat at the same time the next sucker counter-clockwise is caused to belowered, as before described just above the stack of compact discs atthe load position. The suction to that sucker arm located above the discfixture is closed off and vented off through the valve stem. Thisresults from the valve stem on the valve in the sucker arm at thatlocation being depressed as the loading mechanism drops downwardly. SeeFIG. 15. Thus, the compact disc 12 being held by that sucker is nolonger being held by that sucker and drops onto, and into the well 146,of the disc fixture. The centering pin 196, at the same time, is causedto raise vertically upwardly, centering the compact disc 12 justtransferred into the disc fixture, so as to be properly registered inthe fixture well prior to being printed. Suction is applied to thecompact disc 12 just centered holding it firmly in the centered positionin the fixture as the compact disc 12 is transported by the rotatabletransport member 14 through the various work stations e.g. printing,curing, etc., as desired, prior to being off-loaded from the transportmember. At the time that suction is applied to the compact disc beingtransported from location No. 1, the centering pin is caused to retractso that its top is located below the horizontal plane defined by thecompact disc and top surface of the disc fixture. It is important,however, that the centering pin is not withdrawn prior to application ofvacuum to the disc. As earlier disclosed, sensing means can be providedto determine whether a disc is actually being loaded. If not, the vacuumto that disc fixture is not activated. This sensor can be an opticalfiber sensor as before disclosed.

At the same time that the compact disc 12 is dropped onto the discfixture 108 on the transport apparatus 14, the sucker arm located nextadjacent and counterclockwise to that sucker arm from which the compactdisc has just been dropped onto the disc fixture picks up the top-mostcompact disc from the stack of discs at the load station on the feederapparatus, i.e., the second disc vertically downwardly in the originalstack of discs, as before described and transfers it to the loadingpoint on the rotatable transport member 14 at location #1 as the pickand carry unit rotates in clockwise manner, to be loaded onto the nextadjacent disc fixture indexed into that location. As there will be twoempty disc fixtures initially, until completion of three rotations, dueto the indexing of each third location, these two locations can, ifdesired, be loaded by hand prior to activation of the printing system.The next adjacent sucker arm counter-clockwise, i.e., the third suckerarm on the loading mechanism, is then rotated into position at the sametime over the stack of compact discs at the load position on the feedapparatus. The arm 278 pivots downwardly as before and the now top-mostcompact disc 12, i.e., the third disc down in the original stack ofdiscs, is picked up. The second compact disc transferred from the stackof discs is then loaded at the same time, i.e., allowed to drop off thesuction arm onto the compact disc fixture, centered, and suction appliedthereto as before described. The rotatable transport member meanwhilehas indexed to location No. 4 in its circular path of travel. The arm278 on the loading/unloading apparatus pivots downwardly again as asearlier disclosed, the third disc in the stack, now the top-most disc,is picked up by the sucker on the sucker arm. The arm 278 is caused topivot back to the horizontal and the compact disc just picked off thestack is transferred to the loading point at station No. 1 on thetransport member as the loading mechanism rotates in the horizontalplane, as before described. The disc is then loaded (dropped off) ontothe third disc fixture indexed into that location, centered, and vacuumapplied thereto. The indexer 32 meanwhile causes the dial or transportmember to rotate in clockwise manner, causing the fixture with the firstloaded compact disc located therein to pass stations Nos. 2 and 3, thedisc fixture indexing at station No. 4. The second compact disc followsthe same pattern of travel as the first disc, i.e., it indexes paststations 2 and 3, indexing at station 4. The dial continues rotatingclockwise with the first disc passing stations Nos. 5, 6, and indexingat station No. 7, whereat the first-loaded compact disc 12 is printedwith the first color. The dial then continues rotation in a clockwisemanner, the first disc passing stations Nos. 8, 9, indexing at stationNo. 10. Disc No. 2, meanwhile has passed stations Nos. 5, 6, stopping atstation No. 7, to be printed with the first color. The first compactdisc meanwhile has been indexed passed station No. 15 whereat the firstink applied is partially cured by conventional UV-Curing Apparatus. Onetype of such apparatus which will be found suitable and has providedgood results in the practice of the invention is manufactured and soldby Fusion Systems Corporation, Rockville, Md., under the tradedesignation Model F300. It will be appreciated by those skilled in theart, however, that any such apparatus is somewhat dependent upon theparticular ink being applied.

Thus, rotation of the transport member continues until the first compactdisc printed with the first color is indexed beyond the loading station,stopping at station No. 2. The dial continues, indexing each thirdstation, reaching station No. 11 whereat the first compact disc loadedis printed with the second color. The disc applied with the first andsecond colors does not stop at a location where UV curing apparatus islocated. The ink is merely partially cured, on the fly, so-to-speak.

Subsequent to being printed with the second color, the compact disc isultimately indexed to station No. 3 whereat the disc is printed with thethird color, and afterwards fully cured as before described. In someinstances, the ink may only be partially cured at station No. 15. Ifsuch is the case, the ink on the compact disc when indexed to stationNo. 18 is further cured.

Afterwards, the triple printed first loaded compact disc indexes tostation No. 21 whereat it is off-loaded from the annular-shaped rotablemember by the unloading apparatus and placed on a spindle located at theunloading position, to start building a stack of compact discs. Thus,all of the compact discs from the stack are loaded onto the dial,printed, cured, off-loaded from the dial and provided in a stack ofhorizontally disposed printed discs, superposed one above the other.

When the last compact disc is transferred from that first spindle at theloading station, the compact disc sensor 700 senses that there are nomore compact discs on that spindle. As a result, the spindle indexingtable rotates in clockwise manner causing the empty spindle to be movedout of the loading position and the next adjacent spindlecounterclockwise loaded with a stack of compact discs to move from thepreloading position to the loading position. Once there, the cycle justdescribed continues, i.e., the elevator mechanism raises the stack ofdiscs to the sending height, the top disc in that stack is then removed,loaded onto the dial, indexed and printed, cured, and off-loaded, asbefore described. This procedure continues until all the compact discsin the stack on that spindle have been printed and off-loaded and againprovided in a stack of printed discs on an empty spindle located at theunloading station. The action continues until all the compact discswhich are to be printed have been printed and once again provided in aplurality of stacks.

When an empty stacking means is indexed past the loading station on thefeed means that stacking means can then be replaced with a stackingmeans that has been provided with a new stack of discs. Meanwhile, anyempty spindles can be loaded with a stack of compact discs for loadingonto the indexing table, as needed. This action continues until thedesired number of discs have been printed.

In the case of the unloading apparatus, when the stack of discs in theunload position is completed, that stacking means then indexes past theunloading station to the next station clockwise whereat it can beremoved from the indexing table and replaced with an empty stackingmeans. At the same time, a good stacking means in the pre-unloadposition is indexed into the unload position. The receiving apparatusfunctions similar to that described earlier with respect to the feedapparatus, i.e., it has two sensors that monitor for the presence of agood spindle and bobbin. Nevertheless, the receiver module has noelevator mechanism or other moving parts at the unload(load) station andtherefore its operation is much simpler. If a good spindle has beenindexed into the unload position, the receiver is ready to receivediscs. This will be true until the predetermined number of discs havebeen received on the spindle or until the spindle full sensor istripped. When the spindle is determined to be full, the receiver willrequest an index and the cycle will continue.

The control unit 106, as earlier-mentioned, can be provided with variousactivating buttons, control knobs, or the like for performing of variousfunctions, as desired, e.g. start/stop of the systems, indexing of thevarious indexers provided, operation or deactivation of theloading/off-loading apparatus, etc. This unit will contain variouscontrol circuitry interfacing with the PLC. The various inputs/outputsprovided in the PLC will be determined by a predetermined decision treethat determines the operation of the various components comprising thesystem and their synchronization. All of this is within the skill ofthose in the art knowing what functions are to be performed and when.

Although not shown in the drawings, sensing means such as a conventionalcapacitance sensor can be provided in association with the silk-screenprinters and the annular transport member. The purpose of such a sensoris to determine the presence of a compact disc in a disc fixture, bothbefore and after printing, to make certain that a compact disc has notbeen held onto by the printer screen. Such a sensor can be mounted so asto look down onto the disc fixture both before and after the printerstation.

As understood by those skilled in the art, various modifications andchanges can be made in the invention and its form and constructionwithout departing from the spirit and scope thereof. The embodiments ofthe invention disclosed herein are merely exemplary of the variousmodifications that the invention can take and the preferred practicethereof. It is not, however, desired to confine the invention to theexact construction and features shown and described herein, but it isdesired to include all such as properly come within the spirit and scopeof the invention disclosed and claimed.

We claim:
 1. Process for the screen printing of a plurality of compactdiscs one-at-a-time in a predetermined stepwise manner comprising:(a)providing a horizontally disposed rotatable transport member defined bytop and bottom planar surfaces, a plurality vertically disposedcircular-shaped openings being provided in and extending through therotatable transport member from said top planar surface to said bottomplanar surface, said plurality of vertically disposed circular-shapedopenings each being provided in spaced-apart predetermined locations;(b) loading a compact disc onto the rotatable transport member at a saidpredetermined location, said compact disc being characterized by acenterhole and being defined by top and bottom planar surfaces, thecenterhole in the compact disc being located on the compact disc whichis being loaded onto the rotatable transport member above one of saidplurality of circular-shaped openings in the transport member and inconcentric relationship with said one of said plurality ofcircular-shaped openings; (c) raising a vertically disposedcircular-shaped elongated registration pin defined by a top end and abottom end, the pin being located below the bottom planar surface of therotatable transport member and in opposition to said one of saidplurality of circular-shaped openings in the rotatable transport memberand concentric with said one of said plurality of circular-shapedopenings in the rotatatable transport member, a predetermined distancevertically upwardly so that the top end of the vertically disposedelongated circular-shaped registration pin intrudes into the centerholeof the compact disc being loaded onto the rotatable transport memberthereby to register the compact disc in a precise location for thesubsequent application of printing ink to the top surface of the compactdisc; (d) applying vacuum to the bottom surface of the compact discfollowing the registration of the compact disc in said precise locationso as to maintain the compact disc at said precise location for printingwhile being transported to at least one screen printing station whereatthe compact disc is screen printed, and hence to a predeterminedoff-loading station; (e) transporting said compact disc previouslyregistered in said precise location on the rotatable transport member tosaid at least one screen printing station whereat the desiredinformation and color is screen printed on the top surface of thecompact disc; (f) printing the desired information and color on the topsurface of the previously registered compact disc transported to thesaid at least one screen printing station; and (g) further transportingsaid printed compact disc to said predetermined off-loading stationwhereat the compact disc is off-loaded.
 2. Process for the screenprinting of the top surface of a circular-shaped flat object, saidcircular-shaped flat object being characterized by top and bottom planarsurfaces and a centerhole, said process comprising:(a) providing ahorizontally disposed annular-shaped rotatable transport member definedby inner and outer circles of predetermined diameters, the said innerand outer circles being concentric and defining a centerpoint, saidannular-shaped rotatable transport member being further defined by topand bottom planar surfaces, a plurality of vertically disposedspaced-apart circular-shaped openings of a predetermined diameter beingprovided in the annular-shaped rotatable transport member, each saidcircular-shaped opening extending from the top to the bottom planarsurface of the annular-shaped rotatable transport member and beinglocated in predetermined spaced-apart locations, each saidcircular-shaped opening being defined by a centerpoint located on acircle of predetermined radius concentric with the centerpoint of theannular-shaped rotatable transport member and between said inner andouter circles whereby each of said predetermined spaced-apart locationsis defined by the intersection of a radius of the annular-shapedrotatable transport member and said circle of predetermined radiusconcentric with said centerpoint of the annular-shaped rotatabletransport member; (b) providing on the top surface of said rotatabletransport member a plurality of fixtures for said circular-shaped flatobjects, a horizontally disposed circular-shaped well of predetermineddiameter being provided in each said fixture and a circular-shapedopening of a lesser predetermined diameter being provided in each saidwell, the circular-shaped opening in each said well being concentricwith the circular-shaped well, each said fixture being located in apredetermined location on the top planar surface of said annular-shapedrotatable transport member whereby the circular-shaped opening of eachsaid fixture is located directly opposite and superposed above one ofsaid plurally of vertically disposed circular-shaped openings on therotatable transport member; (c) providing below the bottom surface ofthe transport member in opposition to one of said plurality of fixturesa registration means comprising an elongated vertically disposedcircular-shaped registration pin defined by a top end located in directopposition to one of said plurality of vertically disposedcircular-shaped openings in the rotatable transport member; (d) loadinga said circular-shaped flat object onto the rotatable transport memberso that the circular-shaped flat object being loaded is deposited in thewell of one of said plurality of fixtures; (e) raising the elongatedcircular-shaped registration pin vertically upwardly so as to intrudeinto the circular-shaped opening of the well provided in the fixturehence into the centerhole in the circular-shaped flat object whereby thecircular-shaped flat object is precisely registered in a predeterminedlocation in the well of the fixture for subsequent screen printing; (f)applying vacuum to the bottom surface of the circular-shaped flat objectas it is being deposited in the well of the fixture following thecircular-shaped flat object being precisely registered in saidpredetermined location so as to maintain the circular-shaped flat objectat the predetermined location while being transported to at least onescreen printing station; (g) transporting said previously registeredcircular-shaped flat object to said at least one screen printingstation; (h) printing the desired information and color onto the topsurface of the circular-shaped flat object; and (i) further transportingsaid circular-shaped flat object to a predetermined off-loading stationwhereat the circular-shaped flat object is off-loaded.
 3. Process forthe precise registration of a compact disc at a predetermined locationprior to the silk-screen printing of the compact disc, said compact discbeing characterized by a centerhole and by a top planar surface to whichprinting is to be applied and a bottom planar surface on which arecording has been previously provided comprising:(a) providing atransport member characterized by a top and bottom planar surface, aplurality of spaced-apart vertically disposed circular-shaped openingsbeing provided in the transport member each at a said predeterminedlocation for precise registration of a compact disc thereby providing apassageway; (b) providing the centerhole of the compact disc directlyabove one of said plurality of vertically disposed circular-shapedopenings in the transport member; (c) providing a registration meanscomprising a vertically disposed elongated circular-shaped registrationpin having a top end concentric to and in opposition to said one of saidvertically, disposed openings and said predetermined location forprecise registration of the compact disc, said elongated circular-shapedregistration pin being located below the centerhole and the bottomrecorded surface of the compact disc; and (d) raising the verticallydisposed elongated circular-shaped registration pin vertically upwardlyso as to cause the top end of the vertically disposed elongatedregistration pin to intrude into said one of said vertically disposedcircular-shaped openings in the annular-shaped rotatable transportmember and hence into the centerhole of the compact disc located abovesaid one vertically disposed circular-shaped opening provided in saidtransport member.